Cisco IOS Dial Technologies Command Reference, Release 12.2
Commands IS through L2
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isdn all-incoming-calls-v120

Table Of Contents

isdn all-incoming-calls-v120

isdn answer1, isdn answer2

isdn autodetect

isdn bchan-number-order

isdn busy

isdn call interface

isdn caller

isdn calling-number

isdn calling-pty

isdn channel-id invert extended-bit

isdn conference-code

isdn disconnect-cause

isdn disconnect interface

isdn fast-rollover-delay

isdn flip-chan-flag

isdn guard-timer

isdn incoming-voice

isdn layer1-emulate

isdn leased-line bri

isdn map

isdn modem-busy-cause

isdn negotiate-bchan

isdn not-end-to-end

isdn number

isdn nsf-service

isdn outgoing-voice

isdn overlap-receiving

isdn piafs-enabled

isdn point-to-point-setup

isdn protocol-emulate (dial)

isdn reject

isdn send-alerting

isdn sending-complete

isdn service

isdn silent-boot

isdn snmp busyout b-channel

isdn spid1,  isdn spid2

isdn static-tei

isdn switch-type (BRI)

isdn switch-type (PRI)

isdn t306

isdn timer t309

isdn t310

isdn test call interface

isdn test disconnect interface

isdn timer t321

isdn tei-negotiation (global)

isdn tei-negotiation (interface)

isdn transfer-code

isdn twait-disable

isdn v110 only

isdn v110 padding

isdn voice-priority

isdn x25 dchannel

isdn x25 static-tei

l2f ignore-mid-sequence

l2tp drop out-of-order

l2tp flow-control backoff-queuesize

l2tp flow-control maximum-ato

l2tp flow-control receive-window

l2tp flow-control static-rtt

l2tp hidden

l2tp ip udp checksum

l2tp sequencing

l2tp tunnel authentication

l2tp tunnel hello

l2tp tunnel password

l2tp tunnel receive-window

l2tp tunnel retransmit retries

l2tp tunnel retransmit timeout

l2tp tunnel timeout setup

l2tp tunnel zlb delay


isdn all-incoming-calls-v120

To configure an ISDN BRI or PRI interface to answer all incoming calls as V.120 when the terminal adapter uses V.120 signalling but does not send the Lower-Layer Compatibility field in Setup messages, use the isdn all-incoming-calls-v120 command in interface configuration mode. To remove this configuration, use the no form of the command.

isdn all-incoming-calls-v120

no isdn all-incoming-calls-v120

Syntax Description

This command has no arguments or keywords.

Defaults

By default, ISDN interfaces answer calls as synchronous serial with PPP encapsulation.

Command Modes

Interface configuration

Command History

Release
Modification

11.2

This command was introduced.


Usage Guidelines

Use this command only when you want all incoming calls to be answered as V.120. If you want the interface to automatically detect whether the incoming call uses V.120 or PPP encapsulation, use the autodetect encapsulation command.

This command applies only when the incoming call originates on an asynchronous device and needs to terminate in an available vty on the router.

Examples

The following partial example shows that BRI 0 is configured to answer all calls as V.120:

interface bri 0
 isdn all-incoming-calls-v120

Related Commands

Command
Description

autodetect encapsulation

Enables automatic detection of the encapsulation types in operation over a point-to-point link to a specified serial or ISDN interface.


isdn answer1, isdn answer2

To have the router verify a called-party number or subaddress number in the incoming setup message for ISDN BRI calls, if the number is delivered by the switch, use the isdn answer1 command in interface configuration mode. To remove the verification request, use the no form of this command.

isdn answer1 [called-party-number][:subaddress]

no isdn answer1 [called-party-number][:subaddress]

To have the router verify an additional called-party number or subaddress number in the incoming setup message for ISDN BRI calls, if the number is delivered by the switch, use the isdn answer2 command in interface configuration mode. To remove this second verification request, use the no form of this command.

isdn answer2 [called-party-number][:subaddress]

no isdn answer2 [called-party-number][:subaddress]

Syntax Description

called-party-number

(Optional) Telephone number of the called party. At least one value—called-party-number or subaddress—must be specified. The maximum number of digits for called-party-number is 50.

:

(Optional) Identifies the number that follows as a subaddress. Use the colon (:) when you configure both the called party number and the subaddress, or when you configure only the subaddress.

subaddress

(Optional) Subaddress number used for ISDN multipoint connections. At least one value—called-party-number or subaddress—must be specified. The maximum number of digits for subaddress is 50.


Defaults

The router does not verify the called party or subaddress number.

Command Modes

Interface configuration

Command History

Release
Modification

10.3

This command was introduced.


Usage Guidelines

If you do not specify the isdn answer1 or isdn answer2 command, all calls are processed or accepted. If you specify the isdn answer1 or isdn answer2 command, the router must verify the incoming called-party number and the subaddress before processing and/or accepting the call. The verification proceeds from right to left for the called-party number; it also proceeds from right to left for the subaddress number.

You can configure just the called-party number or just the subaddress. In such a case, only that part is verified. To configure a subaddress only, include the colon (:) before the subaddress number.

You can declare a digit a "don't care" digit by configuring it as an x or X. In such a case, any incoming digit is allowed.

Examples

In the following example, 5552222 is the called-party number and 1234 is the subaddress:

interface bri 0
 isdn answer1 5552222:1234

In the following example, only the subaddress is configured:

interface bri 0
 isdn answer1 :1234

isdn autodetect

To enable the automatic detection of ISDN SPIDs and switch type, use the isdn autodetect command in interface configuration mode. To disable the automatic detection of ISDN SPIDs and switch type, use the no form of this command.

isdn autodetect

no isdn autodetect

Syntax Description

This command has no arguments or keywords.

Defaults

The automatic detection of ISDN SPIDs and switch type is disabled.

Command Modes

Interface configuration

Command History

Release
Modification

12.0(3)T

This command was introduced.


Usage Guidelines

This command applies to North America only. If you are outside of North America, you must use the isdn switch-type switch-type interface configuration command to specify the ISDN switch type.

Examples

The following example enables the automatic detection of ISDN SPIDs and switch type:

isdn autodetect

Related Commands

Command
Description

isdn spid1,  isdn spid2

Defines the SPID number that has been assigned by the ISDN service provider for the B1 channel.

isdn switch-type (BRI)

isdn switch-type (PRI)

Specifies the central office switch type on the ISDN BRI or PRI interface.


isdn bchan-number-order

To configure an ISDN PRI interface to make outgoing call selection in ascending or descending order, use the isdn bchan-number-order command in interface configuration mode. To restore the default (descending order), use the no form of this command or simply reconfigure the interface with the new value.

isdn bchan-number-order {ascending | descending}

no isdn bchan-number-order

Syntax Description

ascending

Makes the outgoing B channel selection in ascending order as follows:

Channels 1 to 24 for a T1 controller

Channels 1 to 31 for an E1 controller

descending

Makes the outgoing B channel selection in descending order as follows:

Channels 24 to 1 for a T1 controller

Channels 31 to 1 for an E1 controller


Defaults

Descending

Command Modes

Interface configuration

Command History

Release
Modification

11.3 T

This command was introduced.


Usage Guidelines

This command instructs the router to select the lowest or highest available B channel starting at either channel B1 (ascending) or channel B23 for a T1 and channel B30 for an E1 (descending).

This command is for PRI configuration only.

Examples

The following example configures the outgoing B channel order on a PRI interface to be in ascending order. The router will select the lowest available B channel beginning with channel B1.

interface serial5:10 
 isdn bchan-number-order ascending

isdn busy

To set a false busy signal on an ISDN B channel, use the isdn busy command in interface configuration mode. To remove this condition, use the no form of this command.

isdn busy dsl number b_channel number

no isdn busy dsl number b_channel number

Syntax Description

dsl number

Digital subscriber loop (DSL) number.

b_channel number

B channel or range of B channels to be set to the false busy signal. B channel numbers range from 1 to 24; 0 indicates the entire interface. The state of the channel, which is obtained using the show isdn command with the status keyword, can also be added to the command.


Defaults

Disabled

Command Modes

Interface configuration

Command History

Release
Modification

12.0

This command was introduced.


Usage Guidelines

This command gives the impression that a call is active when the channel is actually idle.

Use the b_channel 0 keywords to set a false busy signal on the entire interface.

Use the show isdn command with the status keyword to display the DSL number and channel state.

Examples

The following example sets the entire PRI interface to a false busy signal; the DSL number was obtained using the show isdn command with the status keyword, and then used in the command.

isdn busy dsl 3 b_channel 0 state 1

The following example sets the false busy signal on B channel 11; the DSL number was obtained using the show isdn command with the status keyword, and then used in the command.

isdn busy dsl 3 b_channel 11 state 2

Related Commands

Command
Description

isdn service

Takes an individual B channel or an entire PRI interface out of service or sets it to a different channel service state that is passed in to the switch.


isdn call interface

To make an ISDN data call, use the isdn call interface command in privileged EXEC mode.

isdn call interface interface-number dialing-string [speed 56 | 64]

Syntax Description

interface-number

Interface number.

dialing-string

Telephone number used for making ISDN data call.

speed 56

speed 64

(Optional) Line speed (56 or 64 kbps) used for making ISDN data call.


Defaults

The default B-channel speed is 64 kbps.

Command Modes

Privileged EXEC

Command History

Release
Modification

12.0(3)T

This command was introduced.


Usage Guidelines

You can use the isdn call interface command to test your DDR configuration. You can also use this command to verify the dialing string and speed without having to know the IP address of the remote router or without configuring a dialer map or string.

The isdn call interface command is being replaced by the isdn test call interface command in Cisco IOS Release 12.2.

Examples

The following example makes an ISDN data call through interface bri 0 to 555-1111 and at a line speed of 56 kbps:

isdn call interface bri 0 5551111 speed 56

Related Commands

Command
Description

isdn disconnect interface

Disconnects an ISDN data call without bringing down the interface.


isdn caller

To configure ISDN caller ID screening and optionally to enable ISDN caller ID callback for legacy dial-on-demand routing (DDR), use the isdn caller command in interface configuration mode. To disable this feature, use the no form of this command.

isdn caller phone-number [callback] [exact]

no isdn caller phone-number [callback] [exact]

Syntax Description

phone-number

Remote telephone number for which to screen. Use the letter X to represent a single "don't care" digit. The maximum length of each number is 25 digits.

callback

(Optional) Enables callback.

exact

(Optional) Performs matching on incoming telephone number exactly as entered.


Defaults

Disabled

Command Modes

Interface configuration

Command History

Release
Modification

10.0

This command was introduced.

11.2 F

This command was implemented on additional Cisco router and access server platforms.

12.1

The exact keyword was added.


Usage Guidelines

This command configures the router to accept calls from the specified number.


Note Caller ID screening requires a local switch or router that is capable of delivering the caller ID to the router. If you enable caller ID screening but do not have such a switch or router, no calls are allowed in. Caller ID screening is available on Cisco 7200 and 7500 series, Cisco 4000 series, Cisco 3000 series, and Cisco 2500 series routers that have one or more BRIs.


When the optional callback keyword is used and a call is received from one of the callback numbers, the initial call is rejected (hence, not subject to tolls) and a callback is initiated to that calling number.

When Xs are used in the callback number, dialer caller screening is based on a best match system that uses the number of Xs as a criterion. To make callback calls only to specified numbers or ranges of numbers but to accept any other incoming calls, make sure that the number of Xs in any configuration line that uses the callback keyword is less than the number of Xs in any configuration line that does not use the keyword.

For example, if you use at most four Xs in the configuration lines with the callback keyword, then to accept calls from other numbers use at least five Xs in a configuration line that does not use the keyword.

When a telephone number is entered without the exact keyword, the software compares each number going from right to left until matching numbers are detected. For example, if the phone-number argument is 4085551234, calls from telephone numbers 1234, 51234, 5551234, and 4085551234 would be accepted, but calls from telephone numbers 44 and 4155551234 would be rejected.

If you want to accept a telephone number exactly as it is configured, enter it with the exact keyword. For example, if the phone-number argument is 5551212 and the exact keyword is applied, only the telephone number 5551212 is accepted; calls from telephone numbers 408551212 and 51212 would be rejected.

The maximum length of each telephone number is 25 characters. There is no limit on the numbers you can specify per interface.

Examples

The following example configures the router to accept a call containing the numbers 415 555-1234:

isdn caller 4155551234

The following example configures the router to accept a call only from telephone number 555-1234:

isdn caller 5551234 exact

In the above example, a call from telephone number 415 555-1234 would be rejected.


The following example configures the router to accept a call with telephone number containing 415 555-12 and any numbers in the last two positions:

isdn caller 41555512xx

In the following example, callback calls will be made only to numbers in the 555 and 556 exchanges, but any other telephone number can call in:

isdn caller 408555xxxx callback
isdn caller 408556xxxx callback
isdn caller xxxxx

Related Commands

Command
Description

show dialer

Displays general diagnostic information for interfaces configured for DDR.


isdn calling-number

To configure an ISDN PRI or BRI interface to present the number of the device making the outgoing call, use the isdn calling-number command in interface configuration mode. To remove a previously configured calling number, use the no form of this command.

isdn calling-number calling-number

no isdn calling-number

Syntax Description

calling-number

Number of the device making the outgoing call; only one entry is allowed.


Defaults

No calling number is presented.

Command Modes

Interface configuration

Command History

Release
Modification

10.3

This command was introduced.


Usage Guidelines

An interface can have only one ISDN calling-number entry.

For ISDN BRI, this command is intended for use when the ISDN network offers TS014 tariffing, in which devices present the calling (billing) number.

For ISDN PRI, this command is intended for use when the network offers better pricing on calls in which devices present the calling number (that is, the billing number). The calling number information is included in the outgoing setup message.


Note This command cannot be used with German 1TR6 ISDN BRI switches. It can be used with all other switches, including all ISDN PRI switches.


Examples

The following example first configures the T1 interface, then configures the D channel interface to present the billing number 4233570925 when it makes outgoing calls:

controller t1 1/1
 framing esf 
 linecode b8zs
 pri-group timeslots 1-23
 isdn switchtype primary-4ess 
!
interface serial 1/1:23
 ip address 10.1.1.1 255.255.255.0
 encapsulation ppp
 isdn calling-number 4233570925
 dialer map ip 10.1.1.2 name dallas 14193460913 

In the following example, the ISDN BRI interface is configured to present the number 5551212 when it makes outgoing calls:

interface bri 0
 isdn calling-number 5551212

Related Commands

Command
Description

interface dialer

Configures a BRI interface and enters interface configuration mode.

interface serial

Specifies a serial interface created on a channelized E1 or channelized T1 controller (for ISDN PRI, CAS, or robbed bit signalling).


isdn calling-pty

To specify whether the network-provided or user-provided calling party number is selected when two calling party numbers are sent from a primary NET5 switch on ISDN, use the isdn calling-pty command in interface configuration mode. To reset the default value, use the no form of this command.

isdn calling-pty {network-provided | user-provided}

no isdn calling-pty

Syntax Description

network-provided

Network-provided calling party number.

user-provided

User-provided calling party number.


Defaults

User-provided calling party number

Command Modes

Interface configuration

Command History

Release
Modification

12.2

This command was introduced for the primary ISDN NET5 switch.


Usage Guidelines

The isdn calling-pty command is useful for customers that use network-provided and user-provided calling party numbers for accounting purposes. The selected number will be used by dialer filters such as that configured with the isdn caller command.

Examples

The following example configures the ISDN switch to accept network-provided calling party numbers:

interface Serial0:23
 no ip address
 encapsulation ppp
 dialer rotary-group 1
 isdn switch-type primary-net5
 isdn protocol-emulate network
 isdn incoming-voice modem
 isdn calling-number 1111111
 isdn calling-pty network-provided
 isdn T310 40000
 no cdp enable

Related Commands

Command
Description

isdn caller

Configures ISDN caller ID screening and optionally enables ISDN caller ID callback for legacy DDR.

isdn calling-number

Configures an ISDN PRI or BRI interface to present the number of the device making the outgoing call.


isdn channel-id invert extended-bit

To invert the value of the extend bit (0x80) in the last octet of the channel ID information element, use the isdn channel-id invert extended-bit command in interface configuration mode. To restore the default setting, use the no form of this command.

isdn channel-id invert extended-bit

no isdn channel-id invert extended-bit

Syntax Description

This command has no arguments or keywords.

Defaults

The last octet of the channel ID information element is not inverted.

Command Modes

Interface configuration

Command History

Release
Modification

12.2

This command was introduced.


Usage Guidelines

Use this command if you use a primary-DMS 100 switch type to ensure compatibility with a Setup or Call Proceeding message containing a channel ID information element. This command can be used only with ISDN PRI.

This command replaces the isdn-flip-chan-flag command.

Examples

The following example configures the router to invert the extended bit in the last octet of the channel ID information element:

isdn channel-id invert extended-bit

isdn conference-code

To activate three-way call conferencing, use the isdn conference-code command in interface configuration mode. To disable three-way call conferencing, use the no form of this command.

isdn conference-code range

no isdn conference-code

Syntax Description

range

Number from 0 to 999 (ISDN conference code).


Defaults

The default code is 60.

Command Modes

Interface configuration

Command History

Release
Modification

12.0(3)T

This command was introduced.


Usage Guidelines

Use this command if your ISDN line is connected to an NI1 or a Nortel DMS-100 Custom switch. Your telephone service provider should provide an ISDN conference code when you order three-way call conferencing.

Examples

The following example specifies 61 as the ISDN conference code:

isdn conference-code 61

isdn disconnect-cause

To send a specific ISDN cause code to the switch, use the isdn disconnect-cause command in interface configuration mode. To return to the default condition, use the no form of this command.

isdn disconnect-cause {cause-code-number | busy | not-available}

no isdn disconnect-cause

Syntax Description

cause-code-number

Sends a cause code number (submitted as integer in the range of 1 through 127) to the switch.

busy

Sends the USER-BUSY code to the switch.

not-available

Sends the CHANNEL-NOT-AVAILABLE code to the switch.


Defaults

The default condition is no cause code override. If the isdn disconnect-cause command is not configured, the default cause codes for the application are sent.

Command Modes

Interface configuration

Command History

Release
Modification

12.0(5)T

This command was introduced.


Usage Guidelines

The isdn disconnect-cause command overrides specific cause codes (such as modem availability and resource pooling) that are sent to the switch by ISDN applications. When the isdn disconnect-cause command is implemented, the configured cause codes are sent to the switch; otherwise, the default cause codes for the application are sent. ISDN protocol errors are still reflected in the cause codes and are not overridden.

Examples

The following example sends the CHANNEL-NOT-AVAILABLE code to the ISDN switch:

interface serial0:20 
 isdn disconnect-cause not-available

Related Commands

Command
Description

isdn disconnect-cause

Sends a specific ISDN cause code to the switch.


isdn disconnect interface

To disconnect an ISDN data call without bringing down the interface, use the isdn disconnect interface command in privileged EXEC mode.

isdn disconnect interface interface-type interface-number {b1 | b2 | all}

Syntax Description

interface-type interface-number

Interface type and number, such as bri 0.

b1

B channel 1.

b2

B channel 2.

all

B channels 1 and 2.


Defaults

A default interface is not defined.

Command Modes

Privileged EXEC

Command History

Release
Modification

12.0(3)T

This command was introduced.


Usage Guidelines

You can use the isdn disconnect interface command to disconnect any ongoing data calls placed manually or caused by DDR.

The isdn disconnect interface command is being replaced by the isdn test disconnect interface command in Cisco IOS Release 12.2.

Examples

The following example disconnects an ISDN data call through interface bri 0 and B channel 1:

isdn disconnect interface bri 0 b1

Related Commands

Command
Description

isdn call interface

Makes an ISDN data call.


isdn fast-rollover-delay

To control the timing between successive dial attempts, use the isdn fast-rollover-delay command in interface configuration mode. To remove or change a value, use the no form of this command.

isdn fast-rollover-delay seconds

no isdn fast-rollover-delay

Syntax Description

seconds

Number of seconds between dial attempts.


Defaults

No default timer.

Command Modes

Interface configuration

Command History

Release
Modification

11.1

This command was introduced.


Usage Guidelines

This command provides a timer separate from the dialer wait-for-carrier timer to control the amount of time that elapses before calls are redialed. This delay is provided to allow the old call to be torn down completely before the new call is attempted.

The isdn fast-rollover-delay command is necessary on some ISDN switches because the new call may be attempted before the old call is completely torn down, which causes the second call or the callback to fail.

Use this command when all the following conditions are true:

A BRI has two phone numbers configured, one for each B channel.

You are dialing in to this BRI.

You have a dialer map or dialer string for each phone number.

The first call succeeds but the second call continuously fails.

When these conditions occur, set the isdn fast-rollover-delay command to 5 seconds and try again. A delay of 5 seconds should cover most cases. Configure sufficient delay to make sure that the ISDN RELEASE_COMPLETE message has been sent or received before the fast rollover call is made. Use the debug isdn q931 command to display this information.

When the isdn fast-rollover-delay command is configured on a client requesting callback, the callback client first confirms whether the callback server has placed a call back to the callback client before dialing any subsequent numbers.

Examples

The following partial example sets the fast-rollover delay that is suggested when all the conditions specified in the list in the "Usage Guidelines" are true:

isdn fast-rollover-delay 5 

Related Commands

Command
Description

dialer map

Configures a serial interface or ISDN interface to call one or multiple sites or to receive calls from multiple sites.

dialer wait-for-carrier-time (map-class)

Specifies the length of time to wait for a carrier when dialing out to the dial string associated with a specified map class.

ppp callback (DDR)

Enables a dialer interface that is not a DTR interface to function either as a callback client that requests callback or as a callback server that accepts callback requests.


isdn flip-chan-flag

The isdn flip-chan-flag command is replaced by the isdn channel-id invert extended-bit command. See the description of the isdn channel-id invert extended-bit command for more information.

isdn guard-timer

To enable a managed timer for authentication requests, use the isdn guard-timer command in interface configuration mode. To reset the timer to its default value, use the no form of this command.

isdn guard-timer msecs [on-expiry {accept | reject}]

no isdn guard-timer

Syntax Description

msecs

Number of milliseconds that the network access server (NAS) waits for a response from the AAA security server. The valid range is from 1000 through 20,000.

on-expiry

(Optional) Determines whether calls are accepted or rejected after the specified number of milliseconds has expired. If no expiry action is selected, calls are rejected.

accept

(Optional) Calls are accepted if the guard-timer expires before AAA responds.

reject

(Optional) Calls are rejected if the guard-timer expires before AAA responds.


Defaults

The default timer value is eight (8) seconds and calls are rejected when the timer expires.

Command Modes

Interface configuration

Command History

Release
Modification

12.1(3)T

This command was introduced.


Usage Guidelines

The guard-timer starts when the DNIS number is sent to AAA for authentication. When the timer expires, authentication ends and the call is accepted or rejected based on the configured expiry action.

Examples

The following example sets the guard-timer to six (6) seconds and specifies that the call should be rejected if AAA does not respond within that interval:

interface serial 1/0/0:23
isdn guard-timer 6000 on-expiry reject

Related Commands

Command
Description

aaa preauth

Enables authentication using DNIS numbers.


isdn incoming-voice

To route all incoming voice calls to the modem and determine how they will be treated, use the isdn incoming-voice command in interface configuration mode. To disable the setting or return to the default, use the no form of this command.

isdn incoming-voice {voice | data [56 | 64] | modem [56 | 64]}

no isdn incoming-voice {voice | data [56 | 64] | modem [56 | 64]}

Syntax Description

voice

Incoming voice calls bypass the modems and be handled as a voice call.

data

Incoming voice calls bypass the modems and be handled as digital data. If this keyword is selected, you can specify a B-channel bandwidth of either 56 kbps or 64 kbps. If no argument is entered, the default value is 64.

modem

Incoming voice calls are passed over to the digital modems, where they negotiate the appropriate modem connection with the far-end modem. If this keyword is selected, you can specify a B-channel bandwidth of either 56 kbps or 64 kbps. If no argument is entered, the default value is 64.


Defaults

data 64

Command Modes

Interface configuration

Command History

Release
Modification

11.1

This command was introduced for ISDN PRI interfaces.

11.1 AA and
12.0(2)XC

This command was implemented on ISDN BRI interfaces.

11.2

This command was enhanced for channelized T1 and integrated into Cisco IOS Release 11.2.

11.3 NA

This command was implemented on additional Cisco router and access server platforms.

12.0(3)T

This command was implemented on additional Cisco router and access server platforms.


Usage Guidelines

Unless you specify otherwise, all calls received by the router and characterized as voice calls are treated as normal ISDN calls, which are handled as digital data and not passed over to the modem. Ordinarily, a data device ignores incoming voice calls, but the tariff structure for data and voice calls might make it less expensive to do "data over voice" calls.

If you use the voice keyword, incoming ISDN voice calls will be treated as voice calls and handled by either a modem or a voice DSP as directed by CSM.

If the default value is configured and the bearer capability of the incoming call is the voice keyword, the call will be rejected.

To answer incoming voice calls at a configured rate (overriding the incoming data rate in the call), use the data keyword.

To establish speedier connections for analog calls to the router, use the isdn incoming-voice command with the modem keyword to have voice calls routed through digital modems (as pulse-code modulated analog data) instead of being treated as digital data.

Configure this command on each D channel in the access server or router. Incoming circuit-switched data calls are not affected by this command.


Note Use the isdn incoming-voice modem command only when you are using ISDN. You must use this command to carry voice over a modem when using ISDN PRI.


Examples

The following example designates incoming ISDN voice calls to be treated as voice calls:

interface 10
 isdn incoming-voice voice

The following example for channelized T1 configures the D channel (hence, all B channels) to answer all incoming voice calls at 56 kbps:

interface serial 0:23
 isdn incoming-voice data 56

The following example routes all incoming voice calls through the modem as analog data:

interface BRI 0/0
 isdn incoming-voice modem

The following example enables incoming and outgoing ISDN calls to route to the modems using the D channel serial interface:

interface serial 0:23
 isdn incoming-voice modem

isdn layer1-emulate

To configure the Layer 1 operation of a BRI voice port as clock master (NT) or slave (TE), use the isdn layer1-emulate command in interface configuration mode. To restore the default (user), use the no form of this command.

isdn layer1-emulate {user | network}

no isdn layer1-emulate

Syntax Description

user

Physical interface operation in clock slave mode (as TE).

network

Physical interface operation in clock master mode (as NT).


Defaults

Layer 1 port operation is as user (TE functionality as clock slave).

Command Modes

Interface configuration

Command History

Release
Modification

12.0(3)XG

This command was introduced on the MC3810.

12.1(3)XI

This command was implemented on the Cisco 2600 and Cisco 3600 series.


Usage Guidelines

If you use the no isdn layer1-emulate network command, the physical layer port operation defaults to user.

Examples

The following example configures the Layer 1 operation of a BRI voice port as QSIG clock slave (TE):

configure terminal
 interface bri 1
 isdn layer1-emulate user

Related Commands

Command
Description

isdn protocol-emulate (dial)

Configures the Layer 2 and Layer 3 port protocol of a BRI voice port or a PRI interface to emulate NT (network) or TE (user) functionality.

network-clock-priority

Specifies the clock-recovery priority for the BRI voice ports in a BVM.


isdn leased-line bri

To configure an ISDN BRI for leased-line service at 128 kbps, use the isdn leased-line bri command in global configuration mode. To remove the configuration, use the no form of this command.

isdn leased-line bri number [128]

no isdn leased-line bri number [128]

Syntax Description

number

BRI interface number.

128

(Optional) Aggregates two B channels into a single pipe at a speed of 128 kbps.


Defaults

Disabled

Command Modes

Global configuration

Command History

Release
Modification

11.2 F

This command was introduced.


Usage Guidelines

Use this command to aggregate two B channels into a single pipe at a speed of 128 kbps. This service is available only for ISDN BRI.

When you use an ISDN BRI interface for access over leased lines, configure the ISDN BRI as a synchronous serial interface. Do not configure ISDN calling and called numbers.

Examples

The following example configures the BRI 0 interface for leased-line access at 128 kbps in Japan.

isdn leased-line bri 0 128

Because of the leased-line—not dialed—environment, configuration of ISDN called and calling numbers is not needed and not used. The BRI 0 interface is henceforth treated as a synchronous serial interface, with the default HDLC encapsulation.

The following example configures the BRI 0 interface for PPP encapsulation:

interface bri 0
 ip address 10.1.1.2 255.255.255.0
 encapsulation ppp
 bandwidth 128

Related Commands

Command
Description

isdn switch-type (BRI)

Specifies the central office switch type on the ISDN BRI interface.


isdn map

To override the default ISDN type and plan generated by the router with custom values, use the isdn map command in interface configuration mode. To revert to the default ISDN type and plan, use the no form of this command.

isdn map {address address | regexp | plan plan | type type}

no isdn map {address address | regexp | plan plan | type type}

Syntax Description

address address

Address map, which can be to either the calling or called number.

regexp

Regular expression for pattern matching.

plan plan

ISDN numbering plan.

type type

ISDN number type.


Defaults

The default is the ISDN type and plan generated by the router.

Command Modes

Interface configuration

Command History

Release
Modification

12.0(6)T

This command was introduced.


Usage Guidelines

This function can be configured on a per-number basis or on numbers that match regular expression patterns. Keywords and arguments for any or all of the possible parameters can be included.

Examples

The following example overrides any plan and type used for any ISDN calls with a called or calling number exactly matching 123:

int serial1:23
   isdn map address 123 plan isdn type unknown 

The following example overrides any plan and type used for ISDN calls with a called or calling number that begins with the numerals 12:

int serial1:23
   isdn map address 12.* plan data type subscriber
 

The following example matches any number ending with the number 7:

int serial1:23
   isdn map address .*7 plan data type subscriber

isdn modem-busy-cause

The isdn modem-busy-cause command is replaced by the isdn disconnect-cause command. See the isdn disconnect-cause command for more information.

isdn negotiate-bchan

To enable the router to accept a B channel that is different from the B channel requested in the outgoing call setup message, use the isdn negotiate-bchan command in interface configuration mode. To restore the default condition, use the no form of this command.

isdn negotiate-bchan [resend-setup]

no isdn negotiate-bchan [resend-setup]

Syntax Description

resend-setup

(Optional) Supports NET5 and NI2 PRI switches only. Specifies that if the requested B channel is not available, the router resends a setup message requesting a different B channel.


Defaults

B-channel negotiation is not enabled. Most PRI switch types set the default channel ID to Exclusive in the setup message. An exception is the NI2 switch which sets the default to Preferred.

This command is the default for thunder dial and thunder voice configurations (Cisco SS7 Interconnect for voice and dial).

Command Modes

Interface configuration

Command History

Release
Modification

11.3

This command was introduced.

12.2

The resend-setup keyword was added for NET5 and NI2 ISDN switches.


Usage Guidelines

The isdn negotiate-bchan command enables the router to negotiate the B channel by setting the channel ID information element to Preferred in the setup message. If this command is not configured, the channel ID is set to the default of the switch, which is usually Exclusive. Exclusive means that only the requested B channel is accepted; if the requested B channel is not available, the call is cleared.

The isdn negotiate-bchan command is supported for all PRI switch types. The resend-setup keyword is supported only for NET5 and NI2 switches. This command is not supported for BRI interfaces.

This command is automatically created when the isdn rlm-group is configured under D channel.

Examples

The following example enables an alternate B channel for serial interface 0:23:

interface serial0:23
 isdn negotiate-bchan

Related Commands

Command
Description

isdn bchan-number-order

Configures an ISDN PRI interface to make outgoing call selection in ascending or descending order.

isdn switch-type (PRI)

Specifies the central office switch type on the ISDN PRI interface.


isdn not-end-to-end

To override the speed that the network reports it will use to deliver the call data, use the isdn not-end-to-end command in interface configuration mode. To disable the configured end-to-end speed, use the no form of this command.

isdn not-end-to-end {56 | 64}

no isdn not-end-to-end

Syntax Description

56

Answers all voice calls at 56 kbps.

64

Answers all voice calls at 64 kbps.


Defaults

The default line speed is 64 kbps.

Command Modes

Interface configuration

Command History

Release
Modification

10.3

This command was introduced.


Usage Guidelines


Note The isdn not-end-to-end command is valid only when an incoming Layer 3 Setup message contains a Progress Information Element in the message. The command is validated on a call-by-call basis, depending upon the message.


This command might be needed to handle incoming calls properly. Although a call might originate at a speed of 56 kbps, the network or internetworking networks might improperly deliver the call to the user at a speed of 64 kbps. This creates a speed mismatch and causes the data to be garbled. Enabling this command makes the router look more closely at the information elements of the incoming call to determine a speed.

A speed mismatch can occur when the source and destination ISDN ports do not belong to the same network.

Examples

The following example sets the line speed for incoming calls to 56 kbps:

isdn not-end-to-end 56

isdn number

To change the maximum number of digits in a called number information element, use the isdn number command in interface configuration mode.

isdn number [called enbloc limit]

Syntax Description

called

Attributes for the ISDN number of the called party.

enbloc

Allows the ISDN terminal to send the ISDN number of the called party in a single SETUP message.

limit

Maximum number of digits allowed in a SETUP message, in the range from 1 to 32.


Defaults

20 digits

Command Modes

Interface configuration

Command History

Release
Modification

12.2

This command was introduced.


Usage Guidelines

The maximum number of digits sent in the initial call SETUP is defaulted to 20 digits. The default of 20 digits chosen because some switches cannot handle more than 20 digits. Some countries in Europe are changing their calling plans and will require calls to be made using more than 20 digits.

The isdn number called enbloc command is used when the maximum number of octets in the called number information element in a SETUP message must be changed from the 20-digit default to the user desired limit. With this command, the user can configure the maximum number from 1 to 32 digits. This command is available for ISDN interfaces and applicable to both BRI and PRI interfaces.


Note This command is enabled for only the following switch types:
BRI_NET3_STYPE
PRI_NET5_SYTPE


Examples

The following example configures the called number information element for 32 digits:

Router(config-if) isdn number called enbloc 32

isdn nsf-service

To configure Network Specific Facilities (NSF) on an ISDN PRI for outgoing calls configured as voice calls, use the isdn nsf-service command in interface configuration mode. To remove NSF on an ISDN PRI, use the no form of this command.

isdn nsf-service {megacom | sdn}

no isdn nsf-service {megacom | sdn}

Syntax Description

megacom

Dial voice calls using AT&T Megacom NSF.

sdn

Dial voice calls using AT&T SDN NSF.


Defaults

Disabled

Command Modes

Interface configuration

Command History

Release
Modification

11.3(5)T

This command was introduced.


Usage Guidelines

This command is used specifically on a PRI (channelized T1) to request NSF services supported on primary AT&T 4ESS (primary-4ess) switch types only.

Examples

The following example sets outgoing voice calls to use AT&T SDN NSF:

interface serial 0:23
 isdn-nsf-service sdn

Related Commands

Command
Description

dialer map

Configures a serial interface or ISDN interface to call one or multiple sites or to receive calls from multiple sites.

dialer voice-call

Configures the dialer map class for an NSF dialing plan to support outgoing voice calls.

map-class dialer

Defines a class of shared configuration parameters associated with the dialer map command for outgoing calls from an ISDN interface and for PPP callback.


isdn outgoing-voice

To set information transfer capability on outgoing calls for all switch types, use the isdn outgoing-voice command in interface configuration mode. To revert to the default state, use the no form of this command.

isdn outgoing-voice {info-transfer-capability {3.1kHz-audio | speech}}

no isdn outgoing-voice

Syntax Description

info-transfer-capability

Specifies information transfer capability for voice calls.

3.1kHz-audio

Sets capability to 3.1 kHz audio.

speech

Sets capability to speech.


Defaults

No information transfer capabilities set.

Command Modes

Interface configuration

Command History

Release
Modification

11.3

This command was introduced.


Usage Guidelines

This command is used on outgoing voice calls only, and sets standard information transfer capability.

Examples

The following example sets information transfer capability on outgoing voice calls to speech:

interface serial 0:23
 isdn outgoing-voice info-transfer-capability speech

Related Commands

Command
Description

isdn incoming-voice

Specifies how to process incoming ISDN voice and data calls.


isdn overlap-receiving

To enable overlap receiving on an ISDN interface, use the isdn overlap-receiving command in interface configuration mode. To disable overlap receiving on an ISDN interface, use the no form of this command.

isdn overlap-receiving [T302 milliseconds]

no isdn overlap-receiving

Syntax Description

T302 milliseconds

(Optional) The number of milliseconds that the T302 timer should wait before expiring. Valid values for the milliseconds argument range from 500 to 20000. The default value is 10000 (10 seconds).


Defaults

Overlap receiving is not enabled.

Command Modes

Interface configuration

Command History

Release
Modification

12.1

This command was introduced.


Usage Guidelines

In some situations, the default timer value of the T302 timer is too long. You can shorten the duration of the timer by specifying the T302 keyword with the number of milliseconds necessary.

When configuring outbound peer matching and overlap receiving, use the isdn overlap-receiving command with the destination-pattern command. You must configure the commands to allow the router to wait for all the digits to be received before the call is routed. To do this, use the T control character after the digits in the destination pattern specified with the destination-pattern command. Optionally, you can shorten the duration of the T302 timer when you specify the isdn overlap-receiving command.

Examples

The following example shows how to enable overlap receiving on the ISDN interface:

interface serial 0:23
 isdn overlap-receiving

The following example shows how to enable overlap receiving on the ISDN interface and set the T302 timer to 2 seconds:

interface serial 0:23
 isdn overlap-receiving T302 2000

Related Commands

Command
Description

destination-pattern

Specifies either the prefix or full E.164 telephone number to be used for a dial peer.

isdn service

Takes an individual B channel or an entire PRI interface out of service or sets it to a different channel service state that is passed in to the switch.


isdn piafs-enabled

To enable the PRI to take PIAFS (Personal Handyphone Internet Access Forum Standard) calls on MICA modems, use the isdn piafs-enabled command in interface configuration mode. To disable the function, use the no form of this command.

isdn piafs-enabled

no isdn piafs-enabled

Syntax Description

This command has no arguments or keywords.

Defaults

No default behavior or values.

Command Modes

Interface configuration

Command History

Release
Modification

12.1(2)XH

This command was introduced.

12.1(3)T

This command was implemented on additional Cisco router and access server platforms.


Examples

The following example enables the PRI to take PIAFS calls:

interface serial 0:23
 isdn piafs-enabled

isdn point-to-point-setup

To configure the ISDN port to send SETUP messages on the static TEI, use the isdn point-to-point-setup command in interface configuration mode. To restore the default, use the no form of this command.

isdn point-to-point-setup

no isdn point-to-point-setup

Syntax Description

This command has no arguments or keywords.

Defaults

The BRI port sends SETUP messages on the static TEI (TEI 127).

Command Modes

Interface configuration

Command History

Release
Modification

12.1(3)XI

This command was introduced.


Usage Guidelines

This command only applies if a static TEI has been activated with the isdn static-tei command.

Examples

The following example configures the BRI port to send SETUP messages on the static TEI:

interface bri 1
isdn point-to-point-setup

Related Commands

Command
Description

isdn tei-negotiation (global)

Configures when Layer 2 becomes active and ISDN TEI negotiation occurs.


isdn protocol-emulate (dial)

To configure the Layer 2 and Layer 3 port protocol of a BRI voice port or a PRI interface to emulate NT (network) or TE (user) functionality, use the isdn protocol-emulate command in interface configuration mode. To restore the default (user), use the no form of this command.

isdn protocol-emulate {user | network}

no isdn protocol-emulate

Syntax Description

user

Layer 2 and Layer 3 port protocol operation as TE (port functions as QSIG slave).

network

Layer 2 and Layer 3 port protocol operation as NT (port functions as QSIG master).


Defaults

Port functions as Q.SIG slave.

Command Modes

Interface configuration

Command History

Release
Modification

12.0(3)XG

This command was introduced on the following platforms: Cisco 2600 series, Cisco 3600 series, and Cisco MC3810 concentrator.


Usage Guidelines

You can use this command to configure the Cisco AS5300 PRI interface to serve as either the primary Q.SIG slave or the primary Q.SIG master. To disable Q.SIG signalling, use the no form of this command.

If you use the no isdn protocol-emulate command, the Layer 2 and Layer 3 protocol emulation defaults to user.

Examples

The following example configures the Layer 2 and Layer 3 function of T1 PRI interface 23 to act as the Q.SIG master (NT):

interface serial 1:23
 isdn protocol-emulate network

The following example configures the Layer 2 and Layer 3 function of a BRI voice port to operate as Q.SIG slave (TE):

interface bri 1
 isdn protocol-emulate user

The following example configures the Layer 2 and Layer 3 function of an E1 PRI interface to operate as Q.SIG slave (TE):

interface serial 1:15
 isdn protocol-emulate user

Related Commands

Command
Description

isdn switch-type (PRI)

Specifies the central office switch type on the ISDN PRI interface.

network-clock-priority

Specifies the clock-recovery priority for the BRI voice ports in a BVM.

pri-group nec-fusion

Configures your NEC PBX to support FCCS

show cdapi

Displays the CDAPI.

show rawmsg

Displays the raw messages owned by the required component.


isdn reject

To reject an incoming ISDN BRI or PRI call based on type, use the isdn reject command in interface configuration mode. To re-allow the incoming call type, use the no form of this command.

isdn reject {{cause cause-code} {data [56 | 64]} | piafs | v110 | v120 | vod | {voice [3.1khz | 7khz | speech]}}

no isdn reject {{cause cause-code} {data [56 | 64]} | piafs | v110 | v120 | vod | {voice [3.1khz | 7khz | speech]}}

Syntax Description

cause cause-code

Rejects call based on cause code value.

data [56 | 64]

Rejects incoming data call. If the optional 56 or 64 keyword is not specified, all data calls, including data over voice, are rejected. Use the optional 56 keyword to reject data coming in at 56 kbps. Use the optional 64 keyword to reject data coming in at 64 kbps.

piafs

Rejects incoming Personal Handyphone Internet Access Forum Standard (PIAFS) calls.

v110

Rejects incoming V.110 calls.

v120

Rejects incoming V.120 calls.

vod

Rejects incoming voice-over-data calls, or calls characterized by 64 kbps unrestricted digital data. Although the bearer capability for these calls indicates an incoming data call, the call is treated as voice over data. See the "Usage Guidelines" for more information.

voice [3.1khz | 7khz | speech]

Rejects incoming voice and modem calls characterized by one of three information transfer capability types: 3.1 kHz, 7 kHz, and speech, which are defined by using, in corresponding order, the 3.1khz, 7khz, and speech keywords. If none of the optional keywords is used, all voice calls except voice over data are rejected.


Defaults

Incoming calls are rejected based on D-channel bearer capability information (cause code 65).

Command Modes

Interface configuration

Command History

Release
Modification

12.0

This command was introduced.

12.2

The cause cause-code keyword and argument were added.


Usage Guidelines

The isdn reject command rejects incoming calls based on D-channel bearer capability information.

If this command is configured with the cause cause-code keyword and argument, it will override the default value and use the configured cause code specified to reject the call. For example, if the isdn reject data command is configured so that data calls are rejected with cause code set to 65 ("bearer capability not implemented" and the default), you can change the cause code to 2, so that data calls will then be rejected with cause code 2. Refer to the ISDN Switch Types, Codes, and Values appendix in the Cisco IOS Debug Command Reference for a list of ISDN cause code values.

The settings for the isdn incoming-voice interface configuration command determine how the call is handled based on bearer capability information, as follows:

isdn incoming-voice voice—Calls bypass the modem and are handled as a voice call.

isdn incoming-voice data—Calls bypass the modem and are handled as digital data.

isdn incoming-voice modem—Calls are passed to a digital modem and the call negotiates the appropriate modem connection with the far-end modem.

When the ISDN interface is configured for incoming voice with the isdn incoming-voice voice command and the ISDN bearer capability indicates the call as unrestricted digital data (i = 0x8890), the call is handled as voice over data.

You can assign as many reject incoming call type statements as needed to reject unwanted calls on the ISDN interface.

This command works on any Cisco platform that supports ISDN PRI and BRI interfaces.

Examples

The following example configuration rejects all incoming data and voice-over-data calls but accepts voice calls:

interface serial 2/0:23
  no ip address
  no logging event link-status
  dialer-group 1
  isdn switch-type primary-net5
  isdn incoming-voice voice
  isdn map address 222 plan isdn type national
  isdn T309 80000
  isdn reject data
  isdn reject vod
  isdn reject v120
  isdn reject v110
  isdn reject piafs

The following example sets the ISDN interface to reject incoming PIAFS calls:

interface serial 2/0:23
 isdn reject piafs

The following example sets cause code 21 to reject all incoming data calls:

interface serial 2/0:23
 isdn reject data
 isdn reject cause 21

Related Commands

Command
Description

isdn incoming-voice

Specifies how to process incoming ISDN voice and data calls.


isdn send-alerting

To specify that an Alerting message be sent before a Connect message when making ISDN calls, use the isdn send-alerting command in interface configuration mode. To disable the Alerting information element, use the no form of this command.

isdn send-alerting

no isdn send-alerting

Syntax Description

This command has no arguments or keywords.

Defaults

This command is disabled by default.

Command Modes

Interface configuration

Command History

Release
Modification

11.3

This command was introduced.


Usage Guidelines

Some switches may want an Alerting message to be sent by the router before sending a Connect message. This is usually seen in a voice and data type of network.

Examples

In the following example, the isdn send-alerting command applies to an ISDN BRI interface:

interface BRI0
 description connected to PBX 61886
 ip address 172.26.1.1 255.255.255.0
 encapsulation ppp
 isdn send-alerting
 isdn sending-complete
 dialer idle-timeout 20
 dialer map ip 172.26.1.2 name rudder 61884
 dialer map ip 172.26.1.3 name bosun 61885
 dialer-group 1
 ppp authentication chap

Related Commands

Command
Description

isdn sending-complete

Specifies that the Sending Complete IE is included in the outgoing Setup message.


isdn sending-complete

To specify that the Sending Complete information element (IE) is included in the outgoing Setup message, use the isdn sending-complete command in interface configuration mode. To disable the Sending Complete information element, use the no form of this command.

isdn sending-complete

no isdn sending-complete

Syntax Description

This command has no arguments or keywords.

Defaults

This command is disabled by default.

Command Modes

Interface configuration

Command History

Release
Modification

11.2

This command was introduced.


Usage Guidelines

The Sending Complete IE tells the switch that all the digits and information necessary for the call are contained in this Setup message.

Some switches in some countries want a Sending Complete information element to be included in the outgoing Setup message to indicate that the entire number is included. The Sending Complete IE is required in Hong Kong and Taiwan, and the isdn sending-complete command forces it to be sent.

Examples

In the following example, the isdn sending-complete command applies to an ISDN BRI interface:

interface BRI0
 description connected to PBX 61886
 ip address 172.31.1.1 255.255.255.0
 encapsulation ppp
 isdn sending-complete
 dialer idle-timeout 20
 dialer map ip 172.31.1.2 name rudder 61884
 dialer map ip 172.31.1.3 name bosun 61885
 dialer-group 1
 ppp authentication chap

The following example enables sending complete IE information on a serial interface:

interface serial 0:15
 description connected to PBX 61886
 ip address 10.1.1.1 255.255.255.0
 encapsulation ppp
 isdn sending-complete
 dialer idle-timeout 20
 dialer map ip 10.1.1.2 name rudder 61884
 dialer map ip 10.1.1.3 name goodie 61885
 dialer-group 1
 ppp authentication chap

Related Commands

Command
Description

isdn send-alerting

Specifies that an Alerting message be sent before a Complete message when making ISDN calls.


isdn service

To take an individual B channel or an entire PRI interface out of service or set it to a different channel service state that is passed to a time-division multiplexing (TDM) switch at the Public Switched Telephone Network (PSTN), use the isdn service command in interface configuration mode. To remove the configuration, use the no form of the command.

isdn service [dsl number | nfas-int number] b_channel number state {0 | 1 | 2}

no isdn service

Syntax Description

dsl number

(Optional) Digital subscriber loop number; displayed with the show isdn status command. DSL numbers range from 0 to 31.

nfas-int number

(Optional) The Non-Facility Associated Signalling (NFAS) member interface number that has B channel(s) to which you want to do maintenance.

b_channel number

B channel or range of B channels to be set with the passed-in state value. Specifying number as 0 sets the entire PRI interface to a specified state value. B channel numbers range from 0 to 31 or 0 for the complete interface.

state {0 | 1 | 2}

Desired channel service state to be set on the channels. The following channel service state values are supported:

0—In service. Restore a channel or complete interface to service.

1—Maintenance. "Soft busy."

2—Out of service. Immediately take a channel(s) out of service and drop any active calls.


Defaults

Disabled

Command Modes

Interface configuration

Command History

Release
Modification

11.3

This command was introduced.

12.2

The dsl keyword was made optional.


Usage Guidelines

Use this command to manage channels on ISDN NFAS and Primary Rate Interfaces (PRI) on Cisco routers.

Use the b_channel 0 keyword to set the entire PRI interface to the specified state value.

To display the digital subscriber loop (DSL) number on NFAS interfaces, use the show isdn service EXEC command. To find the NFAS interface value, use the pri-group T1 controller configuration command.

Examples

The following example sets all the PRI B channel on the interface to maintenance state.

isdn service b_channel 0 state 1

The following example restores B channels 2 to 4; the DSL number was obtained using the show isdn command with the status keyword, and then used in the command:

isdn service dsl 2 b_channel 2-4 state 0

The following example sets B channel 13 to 24 to the out-of-service state:

isdn service nfas-int 3 b_channel 13-24 state 1

Related Commands

Command
Description

show isdn

Displays the information about memory, Layer 2 and Layer 3 timers, and the status of PRI channels.


isdn silent-boot

To prevent the transmission and receipt of ISDN packets by the router during the boostrap loading process, use the isdn silent-boot command in global configuration mode. To allow the transmission and receipt of ISDN packets by the router during the boostrap loading process, use the no form of this command.

isdn silent-boot

no isdn silent-boot

Syntax Description

This command has no arguments or keywords.

Defaults

The transmission and receipt of ISDN packets by the router is allowed during the bootstrap process.

Command Modes

Global configuration

Command History

Release
Modification

12.2

This command was introduced.


Usage Guidelines

ISDN traffic will not be sent from any interfaces on the router (ISDN BRI or PRI) when you use the isdn silent-boot command. Disabling the ISDN traffic on the router is appropriate when the router is part of a hunt group that is accepting incoming ISDN calls because you do not want the router to receive calls until after it has reloaded and is ready to accept the incoming calls.

Examples

The following example disables ISDN traffic:

Router(config)# isdn silent-boot

isdn snmp busyout b-channel

To enable PRI B channels to be busied out via SNMP, use the isdn snmp busyout b-channel command in interface configuration mode. To prevent B channels from being busied out via SNMP, use the no form of this command.

isdn snmp busyout b-channel

no isdn snmp busyout b-channel

Syntax Description

This command has no keywords or arguments.

Defaults

The default value is TRUE; that is, setting busyout using SNMP is allowed.

Command Modes

Interface configuration

Command History

Release
Modification

12.1(3)T

This command was introduced.


Usage Guidelines

To busy out B-channels on a PRI, the ISDN switch must support service messages. The isdn snmp busyout b-channel command sets the MIB object, cpmDS0BusyoutAllow, indicating whether or not the switch supports service messages, thereby allowing the busyout of B channels. When the network access server receives an SNMP request for a busyout, it checks the value of this object. If the no isdn snmp busyout b-channel command is configured, the busyout request fails.

Examples

The following example allows the busyout of B-channels for serial interface 0:23:

configure terminal
interface serial 0:23
isdn snmp busyout b-channel

isdn spid1,  isdn spid2

To associate up to three ISDN local directory numbers (LDNs) provided by your telephone service provider to the first service profile identifier (SPID), use the isdn spid1 command in interface configuration mode. To disable the specified SPID and prevent access to the switch, use the no form of this command.

isdn spid1 spid-number ldn [ldn] [ldn]

no isdn spid1 spid-number ldn [ldn] [ldn]

To associate up to three ISDN LDNs provided by your telephone service provider to the second service SPID, use the isdn spid2 interface configuration command. To disable the specified SPID and prevent access to the switch, use the no form of this command.

isdn spid2 spid-number ldn [ldn] [ldn]

no isdn spid2 spid-number ldn [ldn] [ldn]

Syntax Description

spid-number

Number identifying the service to which you have subscribed. This value is assigned by the ISDN service provider and is usually a 10-digit telephone number with additional digits such as 40855522220101.

ldn

(Optional) ISDN LDN, which is a 7-digit number assigned by the service provider. You can optionally specify a second and third LDN.


Defaults

A default SPID number and ISDN local directory numbers are not defined.

Command Modes

Interface configuration

Command History

Release
Modification

10.3

This command was introduced.

12.0(3)T

This command was enhanced with the option of associating the SPID with up to three LDNs.


Usage Guidelines

This command applies only to North America and is required for DMS-100 and National ISDN switches. Typically, DMS-100 and National ISDN switch implementations using BRI interfaces with SPIDS require two TEIs, two SPIDS, and two phone numbers. If you want to take advantage of both B channels, it is advised you configure the router with the LDN value after the SPID.


Note Some DMS-100 and National ISDN switch installations may be configured as a "hunt group" whereby all calls are initially forwarded to the primary number. Under these circumstances, you should not configure the LDN. You can determine this by enabling the debug isdn q931 command. If the endpoint identifier (EID) information element is delivered in the incoming setup message, then the switch is addressing the TEIs with the EID, instead of the LDN.


If you want the SPID to be automatically detected, you can specify 0 for the spid-number argument.

The ISDN switch checks for the LDN to determine whether both channels can be used to transmit and receive data. If there is not an LDN present, then only the B1 channel can be used for full-duplex communication. However, the B2 channel can still be used to make outgoing calls.

If you include the local directory number in the no form of this command, access to the switch is permitted, but the other B channel may not be able to receive incoming calls.

Examples

The following example defines, on the router, a SPID and LDN for the B1 channel:

isdn spid1 41555512130101 5551213

The following example shows how to specify that the SPID should be automatically detected, that the primary ISDN local directory number is 4085551111, and that the secondary number is 4085552222:

isdn spid1 0 4085551111 4085552222

The following example defines, on the router, a SPID and LDN for the B2 channel:

isdn spid2 41555512140101 5551214

The following example specifies that the SPID should be automatically detected, that the primary ISDN local directory number is 4085551111, and that the secondary number is 4085552222:

isdn spid2 0 4085551111 4085552222

Related Commands

Command
Description

isdn autodetect

Enables the automatic detection of ISDN SPIDs and switch type.


isdn static-tei

To configure a static ISDN Layer 2 terminal endpoint identifier (TEI) over the D channel, use the isdn static-tei command in interface configuration mode. To remove a static TEI configuration, use the no form of this command.

isdn static-tei tei-number

no isdn static-tei tei-number

Syntax Description

tei-number

Terminal endpoint identifier, in the range from 0 to 63.


Defaults

Dynamic TEI (no isdn static-tei)

Command Modes

Interface configuration

Command History

Release
Modification

11.3

This command was introduced.


Usage Guidelines

Depending on the telephone company you subscribe to, you may have a dynamically or statically assigned TEI for your ISDN service. The default TEI behavior is dynamic, and the isdn static-tei command changes that behavior to static for the specified service.

When you reconfigure a TEI with the isdn static-tei command, you must activate the configuration using the shutdown and no shutdown commands.

Examples

The following example configures German Anlagenanschluss ISDN lines. These lines are often provided in a group intended to be connected to single ISDN device such as a private branch exchange. To use the Anlagenanschluss ISDN lines on a Cisco router, you must set the TEI to 0, as follows:

Router# configure terminal
Router(config)# interface bri 0
Router(config-if)# isdn static-tei 0
Router(config-if)# shutdown

Router(config-if)# no shutdown

Related Commands

Command
Description

interface bri

Configures a BRI interface and enters interface configuration mode.

isdn x25 static-tei

Configure a static TEI for X.25 over the ISDN D channel.

shutdown

Disables an interface.


isdn switch-type (BRI)

To specify the central office switch type on the ISDN interface, use the isdn switch-type command in global or interface configuration mode. To remove an ISDN switch type, use the no form of this command.

isdn switch-type switch-type

no isdn switch-type switch-type

Syntax Description

switch-type

ISDN service provider switch type. Table 12 in the "Usage Guidelines" section lists the supported switch types.


Defaults

No ISDN switch type is specified.

Command Modes

Global configuration or interface configuration


Note This command can be entered in either global configuration or interface configuration mode. When entered in global configuration mode, the basic-qsig switch type command specifies that the Cisco MC3810 use QSIG signalling on all BRI interfaces; when entered in interface configuration mode, the command specifies that an individual BRI voice interface use QSIG signalling. The interface configuration mode setting overrides the global configuration setting on individual interfaces.


Command History

Release
Modification

9.21

This command was introduced as a global command.

11.3 T

This command was introduced as an interface command.

12.0(3)XG

The basic-qsig and primary-qsig switch type options were added to support BRI QSIG voice signalling.


Usage Guidelines

For the Cisco AS5300 access server, you have the choice of configuring the isdn-switch-type command to support Q.SIG in either global configuration mode or interface configuration mode. When entered in global configuration mode, the setting applies to the entire Cisco AS5300 access server. When entered in interface configuration mode, the setting applies only to the T1/E1 interface specified. The interface configuration mode setting overrides the global configuration setting.

For example, if you have a Q.SIG connection on one line as well as on the PRI port, you can configure the ISDN switch type in one of the following combinations:

Set the global isdn-switch-type command to support Q.SIG and set the interface isdn-switch-type command for interface serial 0:23 to a PRI setting such as 5ess.

Set the global isdn-switch-type command to support PRI 5ess and set the interface isdn-switch-type command for interface serial 1:23 to support Q.SIG.

Configure the global isdn-switch-type command to another setting (such as switch type VN3), set the interface isdn-switch-type command for interface serial 0:23 to a PRI setting, and set the interface isdn-switch-type command for interface serial 1:23 to support Q.SIG.

For the Cisco MC3810 router, if you are using different Cisco MC3810 BRI port interfaces with different ISDN switch types, you can use global and interface commands in any combination, as long as you remember that interface commands always override a global command.

For example, if you have a BRI QSIG switch interface on BRI voice ports 1, 2, 3 and 4, but a BRI 5ess switch interface on BRI backup port 0, you can configure the ISDN switch types in any of the following combinations:

Enter the isdn switch-type basic-qsig global configuration command, and enter the
isdn switch-type bri-5ess command on interface 0.

Enter the isdn switch-type bri-5ess global configuration command, and enter the
isdn switch-type basic-qsig command on interfaces 1, 2, 3, and 4 individually.

Enter the isdn switch-type bri-5ess command on interface 0, and enter the isdn switch-type basic-qsig command on interfaces 1, 2, 3, and 4 individually.

If you use the no isdn switch-type global configuration command, any switch type that was originally entered in global configuration mode is cancelled; however, any switch type originally entered on an interface is not affected. If you use the no isdn switch-type interface configuration command, any switch type configuration on the interface is cancelled.


Note In the Cisco MC3810, ISDN BRI voice ports support only switch type basic-qsig; ISDN BRI backup ports support all other listed switch types, but not basic-qsig.



Note The dial-peer codec command must be configured before any calls can be placed over the connection to the PINX. The default codec type is G729a.


If you are using the Multiple ISDN Switch Types feature to apply ISDN switch types to different interfaces, refer to the chapters "Configuring ISDN BRI" and "Configuring ISDN PRI" in the Cisco IOS Dial Technologies Configuration Guide for additional details.

The Cisco IOS command parser accepts the following switch types: basic-nwnet3, vn2, and basic-net3; however, when viewing the NVRAM configuration, the basic-net3 or vn3 switch types are displayed, respectively.

To remove an ISDN switch type from an ISDN interface, specify the no isdn switch-type switch-type command.

Table 12 lists supported BRI switch types by geographic area.

 

Table 12 ISDN Service Provider BRI Switch Types 

Keywords by Area
Switch Type
Voice/PBX Systems

 basic-qsig

PINX (PBX) switches with QSIG signalling per Q.931

Australia , Europe, UK

 basic-1tr6

German 1TR6 ISDN switch

 basic-net3

NET3 ISDN BRI for Norway NET3, Australia NET3, and New Zealand NET3switch types; ETSI-compliant switch types for Euro-ISDN E-DSS1 signaling system

 vn3

French ISDN BRI switches

Japan

 ntt

Japanese NTT ISDN switches

North America

 basic-5ess

Lucent (AT&T) basic rate 5ESS switch

 basic-dms100

Northern Telecom DMS-100 basic rate switch

 basic-ni

National ISDN switches

All users

 none

No switch defined


Examples

The following example configures the French VN3 ISDN switch type:

isdn switch-type vn3

The following example uses the Multiple ISDN Switch Types feature and shows use of the global ISDN switch type basic-ni keyword (formerly basic-ni1) and the basic-net3 interface-level switch type keyword. ISDN switch type basic-net3 is applied to BRI interface 0 and overrides the global switch setting.

isdn switch-type basic-ni 
! 
interface BRI0 
 isdn switch-type basic-net3

The following example configures the Cisco MC3810 router to use BRI QSIG signalling for all of its BRI voice ports:

isdn switch-type basic-qsig 

The following example configures the Cisco MC3810 to use BRI QSIG signalling for BRI voice
port 1. On port 1, this setting overrides any different signalling set in the previous example.

interface bri 1
 isdn switch-type basic-qsig

The following example configures the Cisco AS5300 to support Q.SIG signalling:

isdn switch-type primary-qsig

isdn switch-type (PRI)

To specify the central office switch type on the ISDN interface, or to configure the Cisco MC3810 PRI interface to support QSIG signalling, use the isdn switch-type command in global or interface configuration mode. To disable the switch or QSIG signalling on the ISDN interface, use the no form of this command.

isdn switch-type switch-type

no isdn switch-type switch-type

Syntax Description

switch-type

Service provider switch type; see Table 13 for a list of supported switches.


Defaults

The switch type defaults to none, which disables the switch on the ISDN interface.

Command Modes

Global configuration or interface configuration


Note This command can be entered in either global configuration mode or in interface configuration mode. When entered in global configuration mode, the setting applies to the entire Cisco MC3810. When entered in interface configuration mode, the setting applies only to the T1/E1 interface specified. The interface configuration mode setting overrides the global configuration setting.


Command History

Release
Modification

9.21

This command was introduced as a global command.

11.3 T

This command was introduced as an interface command.

12.0(2)T

The primary-qsig-slave and primary-qsig master switch type options were added to support PRI QSIG signalling.


Usage Guidelines

You have a choice of configuring the isdn-switch-type command to support QSIG at either the global configuration level or at the interface configuration level. For example, if you have a QSIG connection on one line as well as on the BRI port, you can configure the ISDN switch type in one of the following combinations:

Set the global isdn-switch-type command to support QSIG, and set the interface isdn-switch-type command for the interface bri 0 command to a BRI setting such as 5ess.

Set the global isdn-switch-type command to support BRI 5ess, and set the interface isdn-switch-type command for the interface serial 1:23 command to support QSIG.

Configure the global isdn-switch-type command to another setting (such as switch type VN3), and then set the interface isdn-switch-type command for the interface bri 0 command to a BRI setting, and set the interface isdn-switch-type command for the interface serial 1:23 command to support QSIG.

The voice-port codec command must be configured before any calls can be placed over the connection to the PINX. The default codec type is G729a.

To disable the switch on the ISDN interface, specify the isdn switch-type none command.

Table 13 lists supported PRI switch types by geographic area.


Note If you are using the Multiple ISDN Switch Types feature to apply the ISDN switch types to different interfaces, refer to the chapter "Setting Up Basic ISDN Service" in the Cisco IOS Dial Technologies Configuration Guide for additional details.


  

Table 13 ISDN Service Provider PRI Switch Types

Keywords by Area
Switch Type
Voice/PBX Systems

 primary-qsig

Supports QSIG signaling per Q.931. Network side functionality is assigned with the isdn protocol-emulate command.

Australia and Europe

 primary-net5

NET5 ISDN PRI switch types for Asia, Australia, and New Zealand; ETSI-compliant switches for Euro-ISDN E-DSS1 signaling system.

Japan

 primary-ntt

Japanese ISDN PRI switch.

North America

 primary-4ess

AT&T 4ESS switch type for the United States.

 primary-5ess

AT&T 5ESS switch type for the United States.

 primary-dms100

NT DMS-100 switch type for the United States.

 primary-ni

National ISDN switch type.

All users

 none

No switch defined.


Examples

The following example demonstrates the Multiple ISDN Switch Type Feature. The global ISDN switch type setting is basic-net3. The PRI interface (channelized T1 controller), is configured to use the isdn switch-type primary-net5 command and BRI interface 0 is configured for the isdn switch-type basic-ni command (formerly isdn switch-type basic-ni1).

isdn switch-type basic-net3 
! 
interface serial0:23 
 isdn switch-type primary-net5 
 ip address 172.21.24.85 255.255.255.0 
! 
interface BRI0 
 isdn switch-type basic-ni

The following example configures T1 interface 23 on the Cisco AS5300 to support Q.SIG signalling:

interface serial 1:23
 isdn switch-type primary-qsig

Related Commands

Command
Description

isdn protocol-emulate (dial)

Configures the Layer 2 and Layer 3 port protocol of a BRI voice port or a PRI interface to emulate NT (network) or TE (user) functionality.

pri-group nec-fusion

Configures your NEC PBX to support FCCS.

show cdapi

Displays the CDAPI.

show rawmsg

Displays the raw messages owned by the required component.


isdn t306

To set a timer for disconnect messages received by a router, use the isdn t306 command in interface configuration mode. To reset to the default, use the default or no form of this command.

isdn t306 msecs

default isdn t306

no isdn t306

Syntax Description

msecs

Time, in milliseconds, that the router waits before disconnecting a call after it receives a disconnect message with a progress indicator of 8. Range is 1 to 400000.


Defaults

Default depends on the switch, usually from 5000 to 30000 ms.

Command Modes

Interface configuration

Command History

Release
Modification

12.1(3)XI

This command was introduced.

12.1(5)T

This command was integrated into Cisco IOS Release 12.1(5)T.

12.2(2)XA

This command was implemented on the Cisco AS5400 and Cisco AS5350.

12.2(2)XB1

This command was implemented on the Cisco AS5850.

12.2(11)T

This command was integrated into Cisco IOS Release 12.2(11)T.


Usage Guidelines

The T306 timer is designed for routers that are configured as an ISDN network-side switch. When a router receives a disconnect message with a progress indicator of 8, it disconnects the call after waiting for the specified number of milliseconds (ms) while the in-band announcement or error tone is playing. Be sure to set the timer long enough for the announcement to be heard or the tone to be recognized. This command is used only for disconnect messages with a progress indicator of 8; otherwise, the T305 timer is used. The disable and no forms of this command have the same result: the timer waits for the default number of ms before disconnecting the call.

Examples

The following example sets the T306 timer to 60000 ms for serial interface 0:23:

interface serial 0:23
isdn t306 60000

Related Commands

Command
Description

isdn t309

Changes the value of the timer to clear the network connection, and release the B channel and call reference when a data-link disconnection has occurred.

isdn t310

Changes the value of the T310 timer for Call Proceeding messages.

isdn timer t321

Changes the value of the T321 timer for D channel switchover when the primary D channel fails.


isdn timer t309

To change the value of the T309 timer to clear the network connection and to release the B channel and call reference when a data-link disconnection has occurred, use the isdn timer t309 command in interface configuration mode. To restore the default value, use the no form of this command.

isdn timer t309 milliseconds

no isdn timer t309

Syntax Description

milliseconds

Number of milliseconds (ms) that the router waits before clearing the network connection, and releasing the B channel and call reference. Values are from 0 to 90 ms.


Defaults

90 ms

Command Modes

Interface configuration

Command History

Release
Modification

12.2

This command was introduced.


Usage Guidelines

When a data link layer malfunction occurs, calls that are not in the active state are cleared. For calls that are not in the active state, the T309 timer is started. The timer is stopped when the data link is reconnected. If the T309 timer expires prior to the reestablishment of the data link, the network clears the connection and call to the remote user, sending a disconnect cause of 27 to indicate that the call destination is out of order. The network releases and disconnects the B channel, and releases the call reference, entering the Null state. The T309 timer is mandatory for routers that are configured as an ISDN network-side switch and by default the timer is set to expire after 90 ms. The implementation of the T309 timer is optional for the user side of the network. The isdn timer t309 command is used for changing the value of the T309 timer.


Note Setting the timer to 0 causes the timer expiry to become infinite so that it will never expire.


Examples

The following example sets the T309 timers to 80 ms for serial interface 0:24:

interface serial 0:24
  isdn timer t309 80

Related Commands

Command
Description

isdn t306

Changes the value of the T306 timer to disconnect a call after the router sends a disconnect message.

isdn t310

Changes the value of the T310 timer for Call Proceeding messages.

isdn timer t321

Changes the value of the T321 timer for D channel switchover when the primary D channel fails.


isdn t310

To set a timer for the call proceeding state, use the isdn t310 command interface configuration mode. To reset to the default, use the no form of this command.

isdn t310 msecs

no isdn t310

Syntax Description

msecs

Time, in milliseconds, that the router waits before disconnecting a call after receiving a call proceeding message. Range is 1 to 400000.


Defaults

Default depends on the switch; usually from 5000 to 30000 ms.

Command Modes

Interface configuration

Command History

Release
Modification

12.1(3)XI

This command was introduced.

12.1(5)T

This command was integrated into Cisco IOS Release 12.1(5)T.

12.2(2)XA

This command was implemented on the Cisco AS5350 and Cisco AS5400.

12.2(2)XB1

This command was implemented on the Cisco AS5850.

12.2(11)T

This command was integrated into Cisco IOS Release 12.2(11)T.


Usage Guidelines

The T310 timer starts when a router receives a call proceeding message; it stops when the call exits the call proceeding state, typically when the call moves to the alerting, connect, or progress state. If the timer expires while the call is in the call proceeding state, the router releases the call. Set the timer to match the specific characteristics of your network.

Examples

The following example sets the T310 timer to 40,000 ms for serial interface 0:23:

interface serial 0:23
isdn t310 40000

Related Commands

Command
Description

isdn protocol-emulate

Sets a timer for Disconnect messages.

isdn t306

Changes the value of the T306 timer to disconnect a call after the router sends a disconnect message.

isdn timer t309

Changes the value of the T309 timer to clear the network connection, and to release the B channel and call reference when a data-link disconnection has occurred.

isdn test call interface

Changes the value of the T321 timer for D channel switchover when the primary D channel fails.


isdn test call interface

To make an ISDN data call, use the isdn test call interface command in privileged EXEC mode.

isdn test call interface interface-number dialing-string [speed 56 | 64]

Syntax Description

interface-number

Interface number.

dialing-string

Telephone number used for making ISDN data call.

speed 56

speed 64

(Optional) Line speed (56 or 64 kbps) used for making ISDN data call.


Defaults

The default B-channel speed is 64 kbps.

Command Modes

Privileged EXEC

Command History

Release
Modification

12.2

This command was introduced.


Usage Guidelines

You can use the isdn test call interface command to test your DDR configuration. You can also use this command to verify the dialing string and speed without having to know the IP address of the remote router or without configuring a dialer map or string.

The isdn test call interface command replaces the isdn call interface command.

Examples

The following example makes an ISDN data call through interface bri 0 to 555-1111 and at a line speed of 56 kbps:

isdn test call interface bri 0 5551111 speed 56

Related Commands

Command
Description

isdn caller

Disconnects an ISDN data call without bringing down the interface.


isdn test disconnect interface

To disconnect an ISDN data call without bringing down the interface, use the isdn test disconnect interface command in privileged EXEC mode.

isdn test disconnect interface interface-type interface-number {b1 | b2 | all}

Syntax Description

interface-type interface-number

Interface type and number, such as bri 0.

b1

B channel 1.

b2

B channel 2.

all

B channels 1 and 2.


Defaults

A default interface is not defined.

Command Modes

Privileged EXEC

Command History

Release
Modification

12.2

This command was introduced.


Usage Guidelines

You can use the isdn test disconnect interface command to disconnect any ongoing data calls placed manually or caused by DDR.

The isdn test disconnect interface command replaces the isdn disconnect interface command.

Examples

The following example disconnects an ISDN data call through interface bri 0 and B channel 1:

isdn test disconnect interface bri 0 b1

Related Commands

Command
Description

isdn call interface

Makes an ISDN data call.


isdn timer t321

To change the value of the timer for D channel switchover when the primary D channel fails, use the isdn timer t321 command in interface configuration mode. To restore the default value, use the no form of this command.

isdn timer t321 milliseconds

no isdn timer t321

Syntax Description

milliseconds

Number of milliseconds (ms) that the router waits before sending a DL-ESTABLISH request on both D channels to request a switchover. Values are from 0 to 30 ms.


Defaults

30 ms

Command Modes

Interface configuration

Command History

Release
Modification

12.2

This command was introduced.


Usage Guidelines

The T321 timer must be implemented when you use the D channel backup procedure involving D channel switchover. The isdn timer t321 command is used for changing the value of the T321 timer.


Note Setting the timer to 0 causes the timer expiry to become infinite so that it will never expire.


Examples

The following example sets the T321 timers to 25 ms for serial interface 0:23:

interface serial 0:23
 isdn timer t321 25

Related Commands

Command
Description

isdn t306

Changes the value of the T306 timer to disconnect a call after the router sends a disconnect message.

isdn timer t309

Changes the value of the T309 timer to clear the network connection, and to release the B channel and call reference when a data-link disconnection has occurred.

isdn t310

Changes the value of the T310 timer for Call Proceeding messages.


isdn tei-negotiation (global)

To configure when Layer 2 becomes active and ISDN terminal endpoint identifier (TEI) negotiation occurs, use the isdn tei-negotiation command in global configuration mode. To remove TEI negotiation configuration, use the no form of this command.

isdn tei-negotiation [first-call | powerup]

no isdn tei-negotiation

Syntax Description

first-call

(Optional) ISDN TEI negotiation should occur when the first ISDN call is placed or received.

powerup

(Optional) ISDN TEI negotiation should occur when the router is powered on.


Defaults

The powerup state is the default condition.

Command Modes

Global configuration

Command History

Release
Modification

9.21

This command was introduced as a global command.


Usage Guidelines

This command is for BRI configuration only.

This command is useful for switches that may deactivate Layers 1 and 2 when there are no active calls or primary DMS-100 switches which activate TEI when the first ISDN call is placed or received.

Examples

The following example applies the isdn tei negotiation first-call command to BRI interface 0. BRI interface 1 will use the isdn tei negotiation powerup command, which is the default setting. Defaults settings do not appear in the router configuration.

isdn switch-type basic-net
!
interface bri0
! Configure the ISDN switch type on this interface and set TEI negotiation to first-call.
 isdn switch-type basic-ni
 isdn tei-negotiation first-call
! BRI interface 1 uses the default TEI negotiation value.
interface bri1

isdn tei-negotiation (interface)

To configure when Layer 2 becomes active and ISDN terminal endpoint identifier (TEI) negotiation occurs, use the isdn tei-negotiation command in interface configuration mode. To remove TEI negotiation from an interface, use the no form of this command.

isdn tei-negotiation {first-call | powerup} {preserve | remove}

no isdn tei-negotiation {first-call | powerup} {preserve | remove}

Syntax Description

first-call

ISDN TEI negotiation should occur when the first ISDN call is placed or received.

powerup

ISDN TEI negotiation should occur when the router is powered on.

preserve

Preserves dynamic TEI negotiation when ISDN Layer 1 flaps, and when the clear interface or the shut and no shut EXEC commands are executed.

remove

Removes dynamic TEI negotiation when ISDN Layer 1 flaps, and when the clear interface or the shut and no shut EXEC commands are executed.


Defaults

The powerup state is the default condition. Depending upon the ISDN switch type configured, the default will be to preserve or remove the TEI negotiation options. See the "Usage Guidelines" and "Examples" sections for further explanation.

Command Modes

Interface configuration

Command History

Release
Modification

11.3 T

This command was introduced as an interface command.

12.2

The preserve and remove keywords were added.


Usage Guidelines

This command is for BRI configuration only.

The first-call and powerup, and preserve and remove command pairs are mutually exclusive, that is, you must choose only one command from either the first-call and powerup or preserve and remove command pairs, per command line.

The no isdn tei-negotiation command returns the configuration to default to the powerup state.

The preserve keyword depends on the ISDN switch type configured, that is, the TEI negotiation configured will be preserved during ISN Layer 1 flaps, and when the clear interface or the shut and no shut EXEC commands are executed, on the switch types listed in Table 14.

Table 14 Switch Types with Preserved TEI Negotiation 

Switch Type
Cisco IOS Keyword

French ISDN switch types

vn2, vn3

Lucent (AT&T) basic rate 5ESS switch

basic-5ess

Northern Telecom DMS-100 basic rate switch

basic-dms100

National ISDN basic rate switch

basic-ni

PINX (PBX) switches with QSIG signaling per Q.931

basic-qsig


For all other ISDN switch types, the TEI negotiation will be removed during ISDN Layer 1 flaps, and when the clear interface or the shut and no shut EXEC commands are executed. Use the remove keyword to specifically set one of the switches listed in Table 14 to the remove state.

Examples

The following example shows the ISDN TEI negotiation configuration with default settings. (Defaults settings do not appear in the router configuration.)

interface BRI0/0
 no ip address
 isdn switch-type basic-ni
 cdapi buffers regular 0
 cdapi buffers raw 0
 cdapi buffers large 0

The following example shows how to set TEI negotiation timing to the first call:

Router(config-if)# isdn tei-negotiation first-call
Router(config-if)# exit
Router(config)# exit
Router# show startup-config
.
.
.
interface BRI0/0
 no ip address
 isdn switch-type basic-ni
 isdn tei-negotiation first-call
 cdapi buffers regular 0
 cdapi buffers raw 0
 cdapi buffers large 0interface BRI0/0

The following example shows how to change TEI negotiation timing back to the default power-up state:

Router(config-if)# no isdn tei-negotiation first-call
Router(config-if)# exit
Router(config)# exit
Router# show startup-config
.
.
.
interface BRI0/0
 no ip address
 isdn switch-type basic-ni
 cdapi buffers regular 0
 cdapi buffers raw 0
 cdapi buffers large 0

The following example shows how to remove TEI negotiation when ISDN Layer 1 flaps (the preserve state is the default for the National ISDN basic rate switch):

Router(config-if)# isdn tei-negotiation remove
Router(config-if)# exit
Router(config)# exit
Router# show startup-config
.
.
.
interface BRI0/0
 no ip address
 isdn switch-type basic-ni
 isdn tei-negotiation first-call
 isdn tei-negotiation remove
 cdapi buffers regular 0
 cdapi buffers raw 0
 cdapi buffers large 0
 

The following example shows how to return the National ISDN basic rate switch to its default preserve state:

Router(config-if)# no isdn tei-negotiation remove
Router(config-if)# exit
Router(config)# exit
Router# show startup-config
.
.
.
interface BRI0/0
 no ip address
 isdn switch-type basic-ni
 isdn tei-negotiation first-call
 cdapi buffers regular 0
 cdapi buffers raw 0
 cdapi buffers large 0

isdn transfer-code

To activate call transferring, use the isdn transfer-code command in interface configuration mode. To disable call transferring, use the no form of this command.

isdn transfer-code range

no isdn transfer-code

Syntax Description

range

Number from 0 to 999 (ISDN transfer code).


Defaults

The default code is 61.

Command Modes

Interface configuration

Command History

Release
Modification

12.0(3)T

This command was introduced.


Usage Guidelines

Use this command if your ISDN line is connected to a NI1 or a Nortel DMS-100 Custom switch. Your telephone service provider should issue an ISDN transfer code when you order call transferring.

Examples

The following example specifies 62 as the ISDN transfer code:

isdn transfer-code 62

isdn twait-disable

To delay a National ISDN BRI switch a random time before activating the Layer 2 interface when the switch starts up, use the isdn twait-disable command in interface configuration mode. To remove the delay, use the no form of this command.

isdn twait-disable

no isdn twait-disable

Syntax Description

This command has no arguments or keywords.

Defaults

This command is enabled by default.

Command Modes

Interface configuration

Command History

Release
Modification

11.3

This command was introduced.


Usage Guidelines

The random-length delay set by this command prevents mass power failures from causing the network ISDN switches to be overwhelmed when power returns and all the devices startup at the same time.

The random delay is in the range 1 to 300 seconds.

Examples

The following example configures a random wait period after a power failure:

isdn twait-disable

isdn v110 only

To selectively accept incoming V.110 calls based on data bit, parity, and stop bit modem communication settings, use the isdn v110 only command in interface configuration mode. To change or disable the expected incoming V.110 modem call configuration, use the no form of this command.

isdn v110 only [databits {5 | 7 | 8}] [parity {even | mark | none | odd | space}]
[
stopbits {1 | 1.5 | 2}]

no isdn v110 only

Syntax Description

databits {5 | 7 | 8}

(Optional) Allowed data bits, as follows:

5—Allow 5 data bits only.

7—Allow 7 data bits only.

8—Allow 8 data bits only.

parity {even | mark | none | odd | space}

(Optional) Allowed parity, as follows:

even—Allow even parity only.

mark—Allow mark parity only.

none—Allow no parity only.

odd—Allow odd parity only.

space—Allow space parity only.

stopbits {1 | 1.5 | 2}

(Optional) Allowed stop bits, as follows:

1—Allow 1 stop bit only.

1.5—Allow 1.5 stop bits only.

2—Allow 2 stop bits only.


Defaults

No default behavior or values.

Command Modes

Interface configuration

Command History

Release
Modification

12.1(4)T

This command was introduced.


Usage Guidelines

The isdn v110 only command provides a way to screen incoming V.110 modem calls and reject any calls that do not have the communication settings configured as the network expects them to be.

Examples

The following example filters out all V.110 modem calls except those with communication settings of 8 data bits, no parity bit, and 1 stop bit:

interface serial 0:23
  isdn v110 only databits 8 parity none stopbits 1

isdn v110 padding

To disable the padded V.110 modem speed report required by the V.110 modem standard, use the
no isdn v110 padding command in interface configuration mode. To reenable the padded V.110 modem speed report, use the isdn v110 padding command.

no isdn v110 padding

isdn v110 padding

Syntax Description

This command has no arguments or keywords.

Defaults

V.110 modem speed padding is enabled.

Command Modes

Interface configuration

Command History

Release
Modification

12.2(8)T

This command was introduced.


Usage Guidelines

The no isdn v110 padding command is useful for networks with devices such as terminal adapters (TAs) and global system for mobile communication (GSM) handsets that do not fully conform to the V.110 modem standard. The V.110 modem standard specifies that the incoming asynchronous data must be padded by adding stop elements to fit the nearest channel rate. For example, a 14400 bits per second (bps) user data signaling rate is adapted to a synchronous 19200-bps stream rate. The software reports the adapted rate (19200 bps) to the modem for an incoming V.110 call. However, for those devices that do not fully conform to the V.110 supplications, the software must report the speed as 14400 instead of 19200 to the modem for a successful connection. By setting the modem interface to no isdn v110 padding, padding is disabled and the actual bit rate can be reported to the modem.

Examples

The following example shows how to disable V.110 asynchronous-to-synchronous padding:

!
 interface Serial0:23
  no ip address
  isdn switch-type primary-ni
  isdn bchan-number-order ascending
  no isdn v110 padding
  no cdp enable

isdn voice-priority

To control the priority of data and voice calls for the telephones, fax machines, and modems connected to the router telephone ports, use the isdn voice-priority command in interface configuration mode. To disable a specified ISDN voice priority setting and to use the default setting, use the no form of this command.

isdn voice-priority local-directory-number {in | out} {always | conditional | off}

no isdn voice-priority local-directory-number

Syntax Description

local-directory-number

Local ISDN directory number assigned by your telephone service provider.

in

Incoming voice call.

out

Outgoing voice call.

always

Always bump a data call for a voice call.

conditional

Bump a data call only if there is more than one call to the same destination.

off

Never bump a data call for a voice call.


Defaults

A data call is never bumped for an incoming or outgoing voice call.

Command Modes

Interface configuration

Command History

Release
Modification

12.0(3)T

This command was introduced.


Usage Guidelines

If an ISDN circuit endpoint is busy with a data call or calls and either a voice call comes in (incoming) or you attempt to place a voice call (outgoing), the data call is handled according to the setting of isdn voice-priority command.

If you are in North America and have multiple ISDN directory numbers associated with a SPID, the outgoing voice priority that you set for any of these directory numbers applies to the other directory numbers. For example, if you enter the following commands, the outgoing voice priority for all directory numbers specified in the isdn spid1 command is set to conditional:

isdn spid1 0 4085551111 4085552222 4085553333
isdn voice-priority 5551111 out conditional

The setting of the pots dialing-method command affects when you hear a busy signal in the following situation:

A data call cannot be bumped.

You are trying to make an outgoing call.

If the setting is overlap, you hear a busy signal when you pick up the handset. If the setting is enblock, you initially hear a dial tone and then a busy signal.

Examples

The following example specifies that a data call for the specified ISDN directory number never be bumped for an incoming or an outgoing voice call:

isdn voice-priority 5551111 in off
isdn voice-priority 5551111 out off

Related Commands

Command
Description

isdn spid1,  isdn spid2

Defines the SPID number that has been assigned by the ISDN service provider for the B1 channel.

pots dialing-method

Specifies how the Cisco 800 series router collects and sends digits dialed on your connected telephones, fax machines, or modems.


isdn x25 dchannel

To create a configurable interface for X.25 traffic over the ISDN D channel, use the isdn x25 dchannel command in interface configuration mode. To remove the interface, use the no form of this command.

isdn x25 dchannel

no isdn x25 dchannel

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release
Modification

11.2 F

This command was introduced.


Usage Guidelines

This command creates a new, configurable interface, which can be specified as interface brix:0 in commands, where x is the original BRI interface number. For example, on a Cisco 4500 router
with an MBRI, if the isdn x25 dchannel command is configured on bri5, the new interface
is bri5:0 and can be used for configuring the other parameters for X.25 over the D channel. These parameters include the addresses, the map statements, and others. To display the new interface, use the more system:running-config command.

Examples

The following example creates interface bri 1:0 and configures it for X.25 over the ISDN D channel. This example uses dynamic TEIs, not a static TEI.

interface bri1
 isdn x25 dchannel
interface bri1:0
 ip address 10.1.1.2 255.255.255.0
 x25 address 31107000000100
 x25 htc 1
 x25 suppress-calling-address
 x25 facility windowsize 2 2
 x25 facility packetsize 256 256
 x25 facility throughput 9600 9600
 x25 map ip 10.1.1.3 31107000000200
 x25 map ip 10.1.1.4 31107000000800

Related Commands

Command
Description

interface bri

Configures a BRI interface and enters interface configuration mode.


isdn x25 static-tei

To configure a static ISDN Layer 2 terminal endpoint identifier (TEI) for X.25 over the ISDN D channel, use the isdn x25 static-tei command in interface configuration mode. Use the no form of this command if dynamic TEIs will be used on the interface that is to carry X.25 traffic over the D channel.

isdn x25 static-tei tei-number

no isdn x25 static-tei tei-number

Syntax Description

tei-number

Terminal endpoint identifier, in the range 0 to 63.


Defaults

Disabled

Command Modes

Interface configuration

Command History

Release
Modification

11.2 F

This command was introduced.


Usage Guidelines

This command applies to ISDN BRI interfaces only. Only one static TEI is allowed per BRI interface. If a second static TEI is configured, the first static TEI is overwritten.

Some switches require a static TEI be used for X.25 over the ISDN D channel.

When the isdn x25 dchannel command is invoked without the isdn x25 static-tei command, a dynamic TEI is chosen.

Examples

The following example creates static TEI 8 on the X.25-over-ISDN-D channel:

interface bri0
 isdn x25 dchannel
 isdn x25 static-tei 8

Because the isdn x25 static-tei command is missing, the following example configuration sets dynamic TEIs for the ISDN channel:

interface bri0
 isdn x25 dchannel

Related Commands

Command
Description

interface bri

Configures a BRI interface and enters interface configuration mode.

isdn x25 dchannel

Creates a configurable interface for X.25 traffic over the ISDN D channel.


l2f ignore-mid-sequence

To ignore multiplex ID (MID) sequence numbers for sessions in an Layer 2 Forwarding (L2F) tunnel, use the l2f ignore-mid-sequence command in VPDN group mode. To remove the ability to ignore MID sequencing, use the no form of this command.

l2f ignore-mid-sequence

no l2f ignore-mid-sequence

Syntax Description

This command has no arguments or keywords.

Defaults

MID sequence number ignoring is disabled.

Command Modes

VPDN group configuration

Command History

Release
Modification

11.3(5)AA

This command was introduced.

12.0(1)T

This command was implemented on additional Cisco router or access server platforms.


Usage Guidelines

This command applies only to L2F initiated tunnels and control packets for initial LCP tunnel negotiation.

This command is not required for Cisco-to-Cisco, LAC-to-LNS tunnel endpoints, and is only required if MID sequence numbering is not supported by a third-party hardware vendor.

Examples

The following example ignores MID sequencing for L2F sessions between a Cisco router and a non-Cisco hardware device, which does not support MID sequencing:

l2f ignore-mid-sequence

l2tp drop out-of-order

To instruct L2TP access concentrator (LAC) or L2TP Network Server (LNS) using Layer 2 Tunneling Protocol (L2TP) to drop packets that are received out of order, use the l2tp drop out-of-order command in VPDN group mode. To disable dropping of out-of-sequence packets, use the no form of this command.

l2tp drop out-of-order

no l2tp drop out-of-order

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

VPDN group configuration

Command History

Release
Modification

11.3(5)AA

This command was introduced.

12.0(1)T

This command was updated for additional Cisco router or access server platforms.


Usage Guidelines

This command is valid only for tunnels where sequencing is enabled.

Examples

The following example causes the LAC or LNS to drop any packets that are received out of order:

l2tp drop out-of-order

l2tp flow-control backoff-queuesize

To define the maximum number of packets that can be queued locally for a session when a peer's receive window is full, use the l2tp flow-control backoff-queuesize command in VPDN group mode. To change the value of the queue size, simply re-enter the command with the new queue size value. To remove a manually configured flow-control backoff value, use the no form of this command.

l2tp flow-control backoff-queuesize queuesize

no l2tp flow-control backoff-queuesize queuesize

Syntax Description

queuesize

Queue size limit on a LAC or LNS so that when the remote peer receive window is full, the LAC or LNS delays sending additional packets.


Defaults

L2TP flow control backoff queueing is enabled and uses a default value of 25.

Command Modes

VPDN group configuration

Command History

Release
Modification

11.3(5)AA

This command was introduced.

12.0(1)T

This command was implemented on additional Cisco router or access server platforms.


Usage Guidelines

This command is used for congestion control. This command will not appear as a valid option if the l2tp flow-control receive-window command is disabled or if the value is set to zero (for sequencing only).

Examples

The following example uses the l2tp flow-control receive-window command option to 8, which in turn enables the l2tp flow-control backoff-queuesize command option. When the remote peer's receive window is full, the maximum number packets that can be queued locally for an L2TP session is 35.

l2tp flow-control receive-window 8
l2tp flow-control backoff-queuesize 35

Related Commands

Command
Description

l2tp flow-control maximum-ato

Defines the maximum adaptive timeout for congestion control.

l2tp flow-control receive-window

Defines the receive window on a LAC or LNS and enables either device to send sequence numbers.


l2tp flow-control maximum-ato

To define the maximum adaptive timeout for congestion control, use the l2tp flow-control maximum-ato command in VPDN group mode. To reset the timeout to a new value, simply reenter the command with the new value. To remove a manually configured timeout value, use the no form of this command.

l2tp flow-control maximum-ato milliseconds

no l2tp flow-control maximum-ato milliseconds

Syntax Description

milliseconds

Wait time period, in milliseconds, before the LAC or LNS probes its remote peer receive-window to resume sending packets.


Defaults

2000 milliseconds

Command Modes

VPDN group configuration

Command History

Release
Modification

11.3(5)AA

This command was introduced.

12.0(1)T

This command was implemented on additional Cisco router or access server platforms.


Usage Guidelines

This command is used for congestion control between the LAC and LNS. This command will not appear as a valid option if the l2tp flow-control receive-window command is disabled or set to zero.

Examples

The following example forces the LAC or LNS to wait 4000 milliseconds before attempting to probe the remote peer's receive status window again:

l2tp flow-control maximum-ato 4000

Related Commands

Command
Description

l2tp flow-control backoff-queuesize

Defines the maximum number of packets that can be queued locally for a session when the receive window of a peer is full.

l2tp flow-control receive-window

Defines the receive window on a LAC or LNS and enables either device to send sequence numbers.


l2tp flow-control receive-window

To define the receive window on a LAC or Layer 2 Tunneling Protocol Network Server (LNS) and enable either device to send sequence numbers, use the l2tp flow-control receive-window command in VPDN group mode. To remove a flow-control receive-window value and disable sequencing, use the no form of this command.

l2tp flow-control receive-window window-size

no l2tp flow-control receive-window window-size

Syntax Description

window-size

The number of packets that can be received by the remote end device before backoff queueing occurs.


Defaults

Receive window and sequence numbers are disabled.

Command Modes

VPDN group configuration

Command History

Release
Modification

11.3(5)AA

This command was introduced.

12.0(1)T

This command was implemented on additional Cisco router or access server platforms.


Usage Guidelines

If the receive-window value is set to zero, then sequence numbers are not sent, and congestion control is not enabled. Data zero length body (ZLB) acknowledgments are not sent when congestion control is disabled. If the receive-window value is greater than zero, then congestion control is enabled, and the value that is configured is sent to the L2TP receive window attribute value pair (AVP).

Using the l2tp flow-control receive-window command with a value greater than zero allows you to configure the following L2TP (optional) commands:

l2tp flow-control maximum-ato

l2tp flow-control backoff-queuesize

If the l2tp flow-control receive-window command is not enabled or the value is set to zero, the l2tp flow-control maximum-ato and 2tp flow-control backoff-queuesize commands will not appear as configurable options by the command parser.

Examples

The following example configures a receive-window value of 25 to be communicated to the remote peer and subsequently enables the configuration of the l2tp flow-control maximum-ato and l2tp flow-control backoff-queuesize commands.

l2tp flow-control receive-window 10 
l2tp flow-control maximum-ato 15 
l2tp flow-control backoff-queuesize 35

Related Commands

Command
Description

l2tp flow-control backoff-queuesize

Defines the maximum number of packets that can be queued locally for a session when the receive window of a peer is full.

l2tp flow-control maximum-ato

Defines the maximum adaptive timeout for congestion control.


l2tp flow-control static-rtt

To define a static round-trip time for congestion control, use the l2tp flow-control static-rtt command in VPDN group mode. To apply a different value, simply reenter the command with the new value. To disable a static round-trip time, use the no form of this command.

l2tp flow-control static-rtt round-trip-time

no l2tp flow-control static-rtt round-trip-time

Syntax Description

round-trip-time

Static round-trip time in milliseconds.


Defaults

Disabled; adaptive timeouts are used.

Command Modes

VPDN group configuration

Command History

Release
Modification

11.3(5)AA

This command was introduced.

12.0(1)T

This command was implemented on additional Cisco router or access server platforms.


Usage Guidelines

If the LAC/LNS is configured to use a static round-trip time, then adaptive time-outs (ATO) are calculated on the fixed round-trip time value configured using the l2tp flow-control static-rtt command. If the device is not configured with the l2tp flow-control static-rtt command, then flow control is automatically calculated based on packet send and receive times. You must have the l2tp-flow control receive-window command enabled with a value greater than zero to use the l2tp flow-control maximum-ato command.

Examples

The following example sets a static round-trip delay of 15000 milliseconds, which in turn disables adaptive timeouts:

l2tp flow-control static-rtt 2500

Related Commands

Command
Description

l2tp flow-control backoff-queuesize

Defines the maximum number of packets that can be queued locally for a session when the receive window of a peer is full.

l2tp flow-control maximum-ato

Defines the maximum adaptive timeout for congestion control.

l2tp flow-control receive-window

Defines the receive window on a LAC or LNS and enables either device to send sequence numbers.


l2tp hidden

To enable Layer 2 Tunneling Protocol (L2TP) attribute-value (AV) pair hiding, which encrypts the AV pair "value," use the l2tp hidden command in VPDN group mode. To disable L2TP AV pair value hiding, use the no form of this command.

l2tp hidden

no l2tp hidden

Syntax Description

This command has no arguments or keywords.

Defaults

L2TP AV pair hiding is disabled.

Command Modes

VPDN group configuration

Command History

Release
Modification

11.3(5)AA

This command was introduced.

12.0(1)T

This command was implemented on additional Cisco router or access server platforms.


Usage Guidelines

This command is not required if one-time PAP password authentication is used. This command is useful for additional security if PPP is using PAP or proxy authentication between the LAC and LNS. When AV pair hiding is enabled, the L2TP hiding algorithm is executed, and sensitive passwords that are used between the L2TP AV pairs are encrypted during PAP or proxy authentication.

In Figure 2, the client initiates a PPP session with the LAC, and tunnel authentication begins. The LAC in turn exchanges authentication requests with the LNS. Upon successful authentication between the LAC and LNS, a tunnel is created. Proxy authentication is done by the LAC using either PAP or CHAP. Since PAP user name and password information is exchanged between devices in clear-text, it is beneficial to use the l2tp hidden command where L2TP AV pair values are encrypted.

Figure 2 LAC-LNS Proxy Authentication

Examples

The following example encrypts the AV pair value exchanged between the LAC and LNS:

l2tp hidden

l2tp ip udp checksum

To enable IP User Data Protocol (UDP) checksums on Layer 2 Tunneling Protocol (L2TP) payload packets, use the l2tp ip udp checksum command in VPDN group configuration mode. To disable IP UDP checksums, use the no form of this command.

l2tp ip udp checksum

no l2tp ip udp checksum

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

VPDN group configuration

Command History

Release
Modification

11.3(5)AA

This command was introduced.

12.0(1)T

This command was implemented on additional Cisco router or access server platforms.


Usage Guidelines

Enabling IP UDP checksum packets causes the switching path to revert to process-level switching, which results in slower performance.

Examples

The following example enables IP UDP checksums on L2TP payload packets:

l2tp ip udp checksum

l2tp sequencing

To enable sequencing for packets sent over a Layer 2 Tunnel Protocol (L2TP) tunnel, use the l2tp sequencing command in VPDN group or VPDN template configuration mode. To disable sequencing, use the no form of this command.

l2tp sequencing

no l2tp sequencing

Syntax Description

This command has no arguments or keywords.

Command Default

Sequencing is disabled by default. However, if the peer device requests sequencing, it will be enabled.

Command Modes

VPDN group configuration
VPDN template configuration

Command History

Release
Modification

12.1

This command was introduced.


Usage Guidelines

Use the l2tp sequencing command to control sequencing for packets sent over an L2TP tunnel.

The l2tp sequencing command configuration may be overridden by a request for sequencing from the peer device. The following sections describe the default behavior and sequencing request interactions of the two tunnel endpoints.

Tunnel Initiator

By default, sequence numbers are off.

By default, the Sequencing Required attribute-value (AV) pair will not be sent from the tunnel initiator to the tunnel terminator.

If the tunnel initiator receives data packets from the tunnel terminator that include sequencing numbers, the tunnel initiator will include sequence numbers on data packets regardless of the l2tp sequencing command configuration.

Enabling the l2tp sequencing command will cause the tunnel initiator to send the Sequencing Required AV pair to the tunnel terminator and to include sequencing numbers on data packets.

Tunnel Terminator

By default, sequence numbers are off.

If the tunnel terminator receives the Sequencing Required AV pair from the tunnel initiator, the tunnel terminator will include sequence numbers on data packets regardless of the l2tp sequencing command configuration.

Enabling the l2tp sequencing command will cause the tunnel terminator to include sequence numbers.

Examples

The following example configures sequencing on a network access server (NAS) for dial-in L2TP tunnels associated with the VPDN group named tunnelme. The NAS will send the Sequencing Required AV pair to the tunnel server, and sequencing will be enabled on both devices.

vpdn-group tunnelme
 request-dialin
  protocol l2tp
  domain cisco.com
!
 local name router32
 initiate to 172.16.1.1
 l2tp sequencing

Related Commands

Command
Description

l2tp drop out-of-order

Instructs a NAS or tunnel server using L2TP to drop packets that are received out of order.

vpdn-group

Creates a VPDN group and enters VPDN group configuration mode.

vpdn-template

Enters VPDN template configuration mode, where a template for VPDN groups can be configured.


l2tp tunnel authentication

To enable Layer 2 Tunneling Protocol (L2TP) tunnel authentication, use the l2tp tunnel authentication command in VPDN group configuration mode. To disable L2TP tunnel authentication, use the no form of this command.

l2tp tunnel authentication

no l2tp tunnel authentication

Syntax Description

This command has no arguments or keywords.

Defaults

Enabled

Command Modes

VPDN group configuration

Command History

Release
Modification

11.3(5)AA

This command was introduced.

12.0(1)T

This command was implemented on additional Cisco router or access server platforms.


Examples

The following example enables L2TP tunnel authentication:

l2tp tunnel authentication

Note L2TP tunnel authentication is enabled by default. Therefore, there is no need to enable this command unless it was previously disabled.


l2tp tunnel hello

To set the number of seconds between sending hello keepalive packets for a Layer 2 Tunneling Protocol (L2TP) tunnel, use the l2tp tunnel hello command in VPDN group configuration mode. To change the tunnel hello value, simply reenter the command with the new value. To disable the sending of hello keepalive packets, use the no form of this command.

l2tp tunnel hello hello-interval

no l2tp tunnel hello hello-interval

Syntax Description

hello-interval

The interval, in seconds, that the LAC and LNS wait before sending the next L2TP tunnel keepalive packet.


Defaults

60 seconds

Command Modes

VPDN group configuration

Command History

Release
Modification

11.3(5)AA

This command was introduced.

12.0(1)T

This command was implemented on additional Cisco router or access server platforms.


Usage Guidelines

The L2TP tunnel keepalive timers do not have use the same value on both sides of the tunnel. For example, a LAC can use a keepalive value of 30 seconds, and an LNS can use the default value of 60 seconds.

Examples

The following example sets the L2TP tunnel hello value to 90 seconds:

l2tp tunnel hello 90

l2tp tunnel password

To set the password that the router will use to authenticate the tunnel, use the l2tp tunnel password command in VPDN group configuration mode. To remove a previously configured password, use the no form of this command.

l2tp tunnel password password

no l2tp tunnel password password

Syntax Description

password

String that the router uses for tunnel authentication.


Defaults

Disabled. If the l2tp tunnel password is not configured, the password associated with the local name is used. If no local name password is configured, the password associated with the host name is used.

Command Modes

VPDN group configuration

Command History

Release
Modification

11.3(5)AA

This command was introduced.

12.0(1)T

This command was implemented on additional Cisco router or access server platforms.


Usage Guidelines

The password defined with the l2tp tunnel password command is also used for attribute-value (AV) pair hiding.

The password hierarchy sequence that is used for tunnel identification and, subsequently, tunnel authentication is as follows:

An L2TP tunnel password is used first (defined by the l2tp tunnel password command).

If no L2TP tunnel password exists, the password associated with the local name is used.

If a local name password does not exist, the password associated with the host name is used.

The username command is used to define the passwords associated with the local name and the host name.

Examples

The following example configures the tunnel password, dustie, which will be used to authenticate the tunnel between local and remote peer:

l2tp tunnel password dustie

Related Commands

Command
Description

hostname

Specifies or modifies the host name for the network server.

local name

Specifies a local host name that the tunnel will use to identify itself.

l2tp hidden

Enables L2TP AV pair hiding, which encrypts the AV pair value.

username

Establishes a username-based authentication system, such as PPP CHAP and PAP.


l2tp tunnel receive-window

To configure the number of packets allowed in the local receive window for a Layer 2 Tunnel Protocol (L2TP) control channel, use the l2tp tunnel receive-window command in VPDN group or VPDN template configuration mode. To restore the default value, use the no form of this command.

l2tp tunnel receive-window packets

no l2tp tunnel receive-window packets

Syntax Description

packets

Number of packets allowed in the receive window. Valid values range from 1 to 5000. The default value varies by platform.


Command Default

The default size of the control channel receive window is platform-dependent.

Command Modes

VPDN group configuration
VPDN template configuration

Command History

Release
Modification

12.0(7) DC

This command was introduced on the Cisco 6400 node route processor (NRP).

12.1(1)

This command was integrated into Cisco IOS Release 12.1(1).


Usage Guidelines

Use the l2tp tunnel receive-window command to set the size of the advertised control channel receive window. The receive window size controls the number of L2TP control packets that can be queued by the system for processing. Increasing the size of the control channel receive window allows the system to open PPP sessions more quickly; a smaller size is desirable on networks that cannot handle large bursts of traffic.

Examples

The following example configures the receive window to hold up to 500 packets for tunnels associated with the virtual private dialup network (VPDN) group named group1:

vpdn-group group1
 l2tp tunnel receive-window 500

Related Commands

Command
Description

vpdn-group

Creates a VPDN group and enters VPDN group configuration mode.

vpdn-template

Creates a VPDN template and enters VPDN template configuration mode.


l2tp tunnel retransmit retries

To configure the number of retransmission attempts made for a Layer 2 Tunnel Protocol (L2TP) control packet, use the l2tp tunnel retransmit retries command in VPDN group or VPDN template configuration mode. To restore the default value, use the no form of this command.

l2tp tunnel retransmit retries number

no l2tp tunnel retransmit retries number

Syntax Description

number

Number of retransmission attempts. Valid values range from 5 to 1000 retries. The default value is 10.


Command Default

The router will resend control packets ten times.

Command Modes

VPDN group configuration
VPDN template configuration

Command History

Release
Modification

12.0(7) DC

This command was introduced on the Cisco 6400 node route processor (NRP).

12.1(1)

This command was integrated into Cisco IOS Release 12.1(1).


Usage Guidelines

Use the l2tp tunnel retransmist retries command to configure the number of times a device will attempt to resend an L2TP control packet.

Examples

The following example tunnels associated with the virtual private dialup network (VPDN) group named group1 to make eight retransmission attempts:

vpdn-group group1
 l2tp tunnel retransmit retries 8

Related Commands

Command
Description

l2tp tunnel busy timeout

Configures the amount of time that the router will wait before attempting to recontact a router that was previously busy.

l2tp tunnel retransmit initial retries

Configures the number of times that the router will attempt to send out the initial L2TP control packet for tunnel establishment before considering a peer busy.

l2tp tunnel retransmit initial timeout

Configures the amount of time that the router will wait before resending an initial L2TP control packet out to establish a tunnel.

l2tp tunnel retransmit timeout

Configures the amount of time that the router will wait before resending an L2TP control packet.

l2tp tunnel timeout no-session

Sets the duration a router waits after an L2TP tunnel becomes empty before tearing down the tunnel.

vpdn-group

Defines a local, unique group name or number identifier.

vpdn-template

Enters VPDN template configuration mode to configure a default template for VPDN groups.


l2tp tunnel retransmit timeout

To configure the amount of time that the router will wait before resending a Layer 2 Tunnel Protocol (L2TP) control packet, use the l2tp tunnel retransmit timeout command in VPDN group or VPDN template configuration mode. To disable a parameter setting, use the no form of this command.

l2tp tunnel retransmit timeout {min | max} seconds

no l2tp tunnel retransmit timeout {min | max} seconds

Syntax Description

min

Specifies the minimum time that the router will wait before resending a control packet.

max

Specifies the maximum time that the router will wait before resending a control packet.

seconds

Timeout length, in seconds, the router will wait before resending a control packet. Valid values range from 1 to 8. The default minimum value is 1. The default maximum value is 8.


Command Default

The router will use the default timeout values specified in the "Syntax Description" section.

Command Modes

VPDN group configuration
VPDN template configuration

Command History

Release
Modification

12.0(7) DC

This command was introduced on the Cisco 6400 node route processor (NRP).

12.1(1)

This command was integrated into Cisco IOS Release 12.1(1).


Usage Guidelines

Control channel retransmissions follow an exponential backoff, starting at the minimum retransmit timeout length specified by the min seconds keyword and argument combination. After each packet that is not acknowledged, the timeout exponentially increases until it reaches the value specified by the max seconds keyword and argument combination. For example, if the minimum timeout length is set to 1 second, the next retransmission attempt occurs 2 seconds later. The following attempt occurs 4 seconds later, and all additional attempts occur in 8-second intervals.

Examples

The following example configures the VPDN group named group1 to make 8 retransmission attempts, with the minimum timeout length set at 2 seconds, and the maximum timeout length set at 4 seconds:

vpdn-group group1
 l2tp tunnel retransmit retries 8
 l2tp tunnel retransmit timeout min 2
 l2tp tunnel retransmit timeout max 4

Related Commands

Command
Description

l2tp tunnel busy timeout

Configures the amount of time that the router will wait before attempting to recontact a router that was previously busy.

l2tp tunnel retransmit initial retries

Configures the number of times that the router will attempt to send out the initial L2TP control packet for tunnel establishment before considering a peer busy.

l2tp tunnel retransmit initial timeout

Configures the amount of time that the router will wait before resending an initial L2TP control packet out to establish a tunnel.

l2tp tunnel retransmit retries

Configures the number of retransmission attempts made for an L2TP control packet.

l2tp tunnel timeout no-session

Sets the duration a router waits after an L2TP tunnel becomes empty before tearing down the tunnel.

vpdn-group

Creates a VPDN group and enters VPDN group configuration mode.

vpdn-template

Enters VPDN template configuration mode, where a template for VPDN groups can be configured.


l2tp tunnel timeout setup

To configure the amount of time that the router will wait for a confirmation message after sending out the initial Layer 2 Tunnel Protocol (L2TP) control packet before considering a peer busy, use the l2tp tunnel timeout setup command in VPDN group or VPDN template configuration mode. To restore the default value, use the no form of this command.

l2tp tunnel timeout setup seconds

no l2tp tunnel timeout setup seconds

Syntax Description

seconds

Time, in seconds, the router will wait for a return message. Valid values range from 60 to 6000 seconds. The default value is 10 seconds.


Command Default

The router will wait 10 seconds for a confirmation message from the peer device before considering it busy.

Command Modes

VPDN group configuration
VPDN template configuration

Command History

Release
Modification

12.1(1)

This command was introduced.


Usage Guidelines

If the router has not received a confirmation message from the peer device before the tunnel timeout setup timer expires, the peer will be placed on the busy list.

Examples

The following example configures a router to wait 25 seconds for confirmation that the initial L2TP control packet was received by the peer. This configuration will apply only to tunnels associated with the virtual private dialup network (VPDN) group named group1.

vpdn-group group1
 l2tp tunnel timeout setup 25

Related Commands

Command
Description

vpdn-group

Creates a VPDN group and enters VPDN group configuration mode.

vpdn-template

Creates a VPDN template and enters VPDN template configuration mode.


l2tp tunnel zlb delay

To configure the delay time before a zero length bit (ZLB) control message must be acknowledged, use the l2tp tunnel zlb delay command in VPDN group or VPDN template configuration mode. To restore the default value, use the no form of this command.

l2tp tunnel zlb delay seconds

no l2tp tunnel zlb delay seconds

Syntax Description

seconds

Maximum number of seconds the router will delay before acknowledging ZLB control messages. Valid values for the seconds argument range from 1 to 5. The default value is 3.


Command Default

The router waits up to 3 seconds before acknowledging ZLB control messages.

Command Modes

VPDN group configuration
VPDN template configuration

Command History

Release
Modification

12.2(10)

This command was introduced.

12.2(11)T

This command was integrated into Cisco IOS Release 12.2(11)T.


Usage Guidelines

Use the l2tp tunnel zlb delay command to change the maximum allowable delay in responding to ZLB messages in a virtual private dialup network (VPDN) deployment. Changing the delay time may be beneficial when the peer device at the other end of the control channel requires a faster response to ZLB messages. This situation can occur if the remote peer has short keepalive timers configured.

Examples

The following example configures control channels associated with the VPDN group named group1 to delay no more than 2 seconds before responding to a ZLB message:

vpdn-group group1
 l2tp tunnel zlb delay 2

Related Commands

Command
Description

vpdn-group

Creates a VPDN group and enters VPDN group configuration mode.

vpdn-template

Enters VPDN template configuration mode, where a template for VPDN groups can be configured.