Table Of Contents
dialer fast-idle (interface configuration)
dialer fast-idle (map-class dialer configuration)
dialer idle-timeout (interface configuration)
dialer idle-timeout (map-class dialer configuration)
dialer string (dialer profiles)
dialer wait-for-carrier-time (interface configuration)
dialer wait-for-carrier-time (map-class dialer configuration)
DDR Commands
This chapter lists dial-on-demand routing (DDR) commands, explains the command syntax, and provides usage guidelines. For information about configuring DDR and for configuration examples, refer to the "Configuring DDR" chapter in the Wide-Area Networking Configuration Guide.
backup delay
To define how much time should elapse before a secondary line status changes after a primary line status has changed, use the backup delay interface configuration command. To return to the default, so that as soon as the primary fails, the secondary is immediately brought up without delay, use the no form of this command.
backup delay {enable-delay | never} {disable-delay | never}
no backup delay {enable-delay | never} {disable-delay | never}Syntax Description
Default
0 seconds
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
For environments in which there are spurious signal disruptions that may appear as intermittent lost carrier signals, we recommend that you enable some delay before activating and deactivating a secondary line.
Example
The following example sets a 10-second delay on deactivating the secondary line (interface serial 0); however, the line is activated immediately:
interface serial 0backup delay 0 10backup interface
To configure an interface as a secondary or dial backup, use the backup interface interface configuration command. To disable this feature, use the no form of this command.
backup interface type number
no backup interface type number
backup interface slot/port (for the Cisco 7000 series)
no backup interface slot/portSyntax Description
type number
Interface type and port number to use as the backup interface.
slot
Slot number of the ATM Interface Processor (AIP) interface.
port
Port number.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.0.
The interface you define with this command can back up only one other interface.
Note
Routers support only serial and ISDN backup interfaces. Access servers support both asynchronous and serial backup interfaces.
Example
The following example sets serial 1 as the backup line for serial interface 0:
interface serial 0backup interface serial 1backup load
To set a traffic load threshold for dial backup service, use the backup load interface configuration command. To return to the default value, use the no form of this command.
backup load {enable-threshold | never} {disable-load | never}
no backup load {enable-threshold | never} {disable-load | never}Syntax Description
Default
No threshold is predefined.
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
When the transmitted or received load on the primary line is greater than the value assigned to the enable-threshold argument, the secondary line is enabled.
The secondary line is disabled when one of the following conditions occurs:
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•
If the never keyword is used instead of an enable-threshold value, the secondary line is never activated because of traffic load. If the never keyword is used instead of a disable-load argument, the secondary line is never activated because of traffic load.
Example
The following example sets the traffic load threshold to 60 percent of the primary line serial 0. When that load is exceeded, the secondary line is activated, and will not be deactivated until the combined load is less than 5 percent of the primary bandwidth.
interface serial 0backup load 60 5backup interface serial 1chat-script
To create a script that will place a call over a modem, use the chat-script global configuration command. To disable the specified chat script, use the no form of this command.
chat-script script-name expect-send
no chat-script script-name expect-sendSyntax Description
Default
No chat scripts are defined.
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Chat scripts are used in dial-on-demand routing (DDR) to give commands to dial a modem and commands to log on to remote systems. The defined script will be used to place a call over a modem.
Some characteristics of chat scripts are as follows:
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We recommend that one chat script (a "modem" chat script) be written for placing a call and another chat script (a "system" or "login" chat script) be written to log on to remote systems, where required.
Suggested Chat Script Naming Conventions
A suggested chat script naming convention is as follows:
vendor-type-modulation
If you follow this convention, the syntax of the chat-script command becomes the following:
chat-script vendor-type-modulation expect-send
For example, if you have a Telebit T3000 modem that uses V.32bis modulation, you would name your chat script as follows:
telebit-t3000-v32bis
The chat-script command could become the following:
chat-script telebit-t3000-v32bis ABORT ERROR ABORT BUSY ABORT "NO ANSWER" "" "AT H" OK "AT DT \T" DIALING \c TIMEOUT 30 CONNECT \cFor example, you could have script names like the following:
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•
•
•
•
•
•
•
•
•
•
•
•
Adhering to this naming convention allows you to use partial chat script names with regular expressions to specify a range of chat scripts that can be used. This capability is particularly useful for dialer rotary groups and is explained further in the next section.
Chat scripts are in the form expect-send, where the send string following the hyphen (-) is executed if the preceding expect string fails. Each send string is followed by a return unless it ends with the escape sequence \c. The sequence ^x is translated into the appropriate control character, and the sequence \x is translated into x if \x is not one of the special sequences listed in .
See the book entitled Managing uucp and Usenet by Tim O'Reilly and Grace Todino for more information about chat scripts.
Escape Sequences
The escape sequences used in chat scripts are listed in Table 8.
Expect-Send Pairs
Sample supported expect-send pairs are described in .
Table 9 Sample Supported Expect-Send Pairs
For example, if a modem reports BUSY when the number dialed is busy, you can indicate that you want the attempt stopped at this point by including ABORT BUSY in your chat script.
Alternate Handlers
If you use the expect-send pair ABORT SINK instead of ABORT ERROR, the system terminates abnormally when it encounters SINK instead of ERROR.
Missed Characters
After the connection is established and you press the Return key, you must often press Return a second time before the prompt appears.
For example, you might include the following as part of your chat script:
ssword:-/r-sswordThis part of the script specifies that, after the connection is established, you want ssword to be displayed. If it is not displayed, you must press Return again after the timeout passes.
Example
The following example shows the chat-script command being used to create a chat script named t3000:
chat-script t3000 ABORT ERROR ABORT BUSY ABORT "NO ANSWER" "" "AT H" OK "AT DT \T" DIALING \c TIMEOUT 30 CONNECT \cRelated Commands
clear dialer
To clear the values of dialer statistics for one or more serial interfaces or Basic Rate Interfaces (BRIs) configured for DDR, use the clear dialer privileged EXEC command.
clear dialer [interface type number]
clear dialer [interface serial slot/port] (Cisco 7000 series only)Syntax Description
Command Mode
Privileged EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 11.0.
If the interface keyword and the arguments are not used, dialer statistics are cleared on all interfaces.
Example
The following example clears the dialer statistics on serial interface 1:
clear dialer interface serial 1clear snapshot quiet-time
To end the quiet period on a client router within two minutes, use the clear snapshot quiet-time EXEC command.
clear snapshot quiet-time interface
Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
The clear snapshot quiet-time command places the client router in a state to reenter the active period within 2 minutes. The 2-minute hold period ensures a quiet period of at least 2 minutes between active periods.
Example
The following example ends the quiet period on dialer interface 1:
clear snapshot quiet-time dialer 1Related Commands
dialer caller
To configure caller ID screening, use the dialer caller interface configuration command. To disable this feature, use the no form of this command.
dialer caller number
no dialer caller numberSyntax Description
number
Telephone number for which to screen. Specify an x to represent a single "don't-care" character. The maximum length of each number is 25 characters.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.0.
This command configures the Cisco IOS software to accept calls from the specified number.
Caller ID screening is available on Cisco 7000 series, Cisco 4000 series, Cisco 3000 series, and Cisco 2500 series that have dialer interfaces.
The maximum length of each number is 25 characters.
Note
Examples
The following example configures a router or access server to accept a call with a delivered caller ID equal to 4155551234:
dialer caller 4155551234The following example configures a router or access server to accept a call with a delivered caller ID having 41555512 and any numbers in the last two positions:
dialer caller 41555512xxRelated Command
dialer dtr
To enable DDR on an interface and specify that the serial line is connected by non-V.25bis modems using Electronic Industries Association (EIA) signaling only—the data terminal ready (DTR) signal—use the dialer dtr interface configuration command. To disable dial-on-demand routing (DDR) for the interface, use the no form of this command.
dialer dtr
no dialer dtrSyntax Description
This command has no keywords or arguments.
Default
DTR dialing is disabled.
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
A serial interface configured for DTR dialing can place calls only; it cannot accept them.
When a local interface is configured for DTR dialing, the remote interface (that will be receiving the calls) can be configured for in-band dialing or not configured for anything but encapsulation, depending on the desired behavior. If the remote interface is expected to terminate a call when no traffic is transmitted for some time, it must be configured for in-band dialing (along with access lists and a dummy dialer string). If the remote interface is purely passive, no configuration is necessary.
Rotary groups cannot be configured for DTR dialing.
The dialer map and dialer string commands have no effect on DTR dialers.
Example
The following example enables DDR and specifies DTR dialing on an interface:
dialer dtrRelated Commands
dialer in-band
dialer map
dialer string (legacy DDR)dialer enable-timeout
To set the length of time an interface stays down after a call has completed or failed and before it is available to dial again, use the dialer enable-timeout interface configuration command. To return to the default value, use the no form of this command.
dialer enable-timeout seconds
no dialer enable-timeoutSyntax Description
Default
15 seconds
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
This command applies to inbound and outbound calls.
If your phone lines are often busy or down, you might want to enforce a certain period of time before the system repeats an attempt to make a connection with a remote site. Configuring this timeout can prevent outgoing lines and switching equipment from being needlessly overloaded.
Example
The following example specifies a waiting period of 30 seconds on interface async 1:
interface async 1dialer enable-timeout 30dialer fast-idle (interface configuration)
To specify the amount of time that a line for which there is contention will stay idle before it is disconnected and the competing call is placed, use the dialer fast-idle interface configuration command. To return to the default value, use the no form of this command.
dialer fast-idle seconds
no dialer fast-idleSyntax Description
seconds
Idle time, in seconds, that must occur on an interface before the line is disconnected. Acceptable values are positive, nonzero integers.
Default
20 seconds
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
The dialer fast idle timer is activated if there is contention for a line. The dialer fast idle timer is activated if a line is busy, a packet for a different next hop address is received, and the busy line is required to send the competing packet.
If the line becomes idle for configured length of time, the current call is disconnected immediately and the new call is placed.
If the line has not yet been idle as long as the fast idle timeout period, the packet is dropped because there is no way to get through to the destination. After the packet is dropped, the fast idle timer remains active and the current call is disconnected as soon as it has been idle for as long as the fast idle timeout.
The fast idle timer will be restarted if, in the meanwhile, another packet is transmitted to the currently connected destination and it is classified as interesting.
This command applies to inbound and outbound calls.
Combining this command with the dialer idle-timeout command allows you to configure lines to stay up for a longer period of time when there is no contention, but to be reused more quickly when there are not enough lines for the current demand.
Example
The following example specifies a fast idle timeout of 35 seconds on interface async 1:
interface async 1dialer fast-idle 35Related Commands
dialer idle-timeout (interface configuration)
dialer mapdialer fast-idle (map-class dialer configuration)
To specify the fast idle timer value to use when placing a call to any telephone number associated with a specified class, use the dialer fast-idle map-class dialer configuration command. To reset the dialer fast-idle timer to the default, use the no form of this command.
dialer fast-idle seconds
no dialer fast-idleSyntax Description
Default
Defaults to the fast idle timer value set for the interface.
Command Mode
Map-class dialer
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
The dialer string class command defines the map class associated with the dial string and interface.
This fast idle timer is associated only with the map class, not the entire interface.
Example
dialer string 4156884540 class Eng! This map-class ensures that these calls use an ISDN speed of 56 kbps.map-class dialer Engisdn speed 56Related Command
dialer string (dialer profiles)
dialer-group
To control access by configuring an interface to belong to a specific dialing group, use the dialer-group interface configuration command. To remove an interface from the specified dialer access group, use the no form of this command.
dialer-group group-number
no dialer-groupSyntax Description
Default
No access is predefined.
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
An interface can be associated with a single dialer access group only; multiple dialer-group assignment is not allowed. A second dialer access group assignment will override the first. A dialer access group is defined with the dialer-group command. The dialer-list command associates an access list with a dialer access group.
Packets that match the dialer group specified trigger a connection request.
Example
The following example specifies dialer access group number 1.
The destination address of the packet is evaluated against the access list specified in the associated dialer-list command. If it passes, either a call is initiated (if no connection has already been established) or the idle timer is reset (if a call is currently connected).
interface async 1dialer-group 1access-list 101 deny igrp 0.0.0.0 255.255.255.255 255.255.255.255 0.0.0.0access-list 101 permit ip 0.0.0.0 255.255.255.255 0.0.0.0 255.255.255.255dialer-list 1 list 101Related Command
dialer hold-queue
To allow interesting outgoing packets to be queued until a modem connection is established, use the dialer hold-queue interface configuration command. To disable the hold queue, use the no form of this command.
dialer hold-queue packets
no dialer hold-queue [packets]Syntax Description
packets
Number of packets, in the range 0 to 100 packets, to hold in the queue. This argument is optional with the no form of the command.
Default
The outgoing packet queue is disabled.
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
A dialer hold queue can be configured on any type of dialer, including in-band synchronous, asynchronous, data terminal ready (DTR), and Integrated Services Digital Network (ISDN) dialers. Rotary groups can be configured with a dialer hold queue. If a rotary group is configured with a hold queue, all members of the group will be configured with a dialer hold queue and no individual member's hold queue can be altered.
If no hold queue is configured, packets are dropped during the time required to establish a connection.
Example
The following command configures a dialer hold queue to hold 10 packets:
dialer hold-queue 10Related Command
dialer idle-timeout (interface configuration)
To specify the idle time before the line is disconnected, use the dialer idle-timeout interface configuration command. To reset the idle timeout to the default, use the no form of this command.
dialer idle-timeout seconds
no dialer idle-timeoutSyntax Description
seconds
Idle time, in seconds, that must occur on the interface before the line is disconnected. Acceptable values are positive, nonzero integers.
Default
120 seconds
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
This command is used on lines for which there is no contention. When contention occurs, the dialer fast-idle command is activated. For example, when a busy line is requested to send another packet to a different destination than it is currently connected to, line contention occurs and the dialer fast-idle command is activated.
This command applies to inbound and outbound calls. For example, if a receiving system needs to make outgoing calls, you might configure it with a short idle timeout.
Only packets that match the dialer group reset the idle timer.
Use the dialer idle-timeout command to set a very high idle timer when multilink PPP is configured and you want a multilink bundle to be connected indefinitely. (The dialer-load threshold 1 command no longer keeps a multilink bundle of n links connected indefinitely and the the dialer-load threshold 2 command no longer keeps a multilink bundle of 2 links connected indefinitely.)
Example
The following example specifies of an idle timeout of 3 minutes (180 seconds) on interface async 1:
interface async 1dialer idle-timeout 180Related Commands
dialer fast-idle (interface configuration)
dialer-groupdialer idle-timeout (map-class dialer configuration)
To specify the idle time before the calls in this map class are disconnected, use the dialer idle-timeout map-class dialer configuration command. To reset the idle timeout to the default, use the no form of this command.
dialer idle-timeout seconds
no dialer idle-timeoutSyntax Description
seconds
Idle time, in seconds, that must occur on an interface associated with a map class before calls are disconnected. Acceptable values are positive, nonzero integers.
Default
Defaults to a value set for the interface.
Command Mode
Map-class configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
The dialer string class command defines the map class associated with the dial string and interface.
Example
The following example sets a dialer idle-timeout interval of 180 seconds:
dialer idle-timeout 180Related Command
dialer string (dialer profiles)
dialer in-band
To specify that dial-on-demand routing (DDR) is to be supported, use the dialer in-band interface configuration command. To disable DDR for the interface, use the no form of this command.
dialer in-band [no-parity | odd-parity]
no dialer in-bandSyntax Description
Default
Disabled. By default, no parity is applied to the dialer string.
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
The dialer in-band command specifies that chat scripts will be used on asynchronous interfaces and V.25bis will be used on synchronous interfaces. The parity keywords do not apply to asynchronous interfaces.
The parity setting applies to the dialer string that is sent out to the modem. If you do not specify a parity, or if you specify no parity, no parity is applied to the output number. If odd parity is configured, the dialed number will have odd parity (7-bit ASCII characters with the eighth bit as the parity bit.)
If an interface only accepts calls and does not place calls, the dialer in-band interface configuration command is the only command needed to configure it. If an interface is configured in this manner, with no dialer rotary groups, the idle timer never disconnects the line. It is up to the remote end (the end that placed the call) to disconnect the line based on idle time.
Example
The following example specifies DDR for asynchronous interface 1:
interface async 1dialer in-bandRelated Commands
dialer map
dialer string (legacy DDR)dialer isdn
To specify the bit rate used on the B channel associated with a specified map class and to specify whether to set up semipermanent connections for this map class, use the dialer isdn map-class configuration command.
dialer isdn [speed speed] [spc]
no dialer isdn [speed speed] [spc]Syntax Description
Default
Bit rate is 64 Kbps. Semipermanent connections are not set up.
Command Mode
Map-class dialer configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
This command is valid for ISDN interfaces only.
Example
The following example configures a speed of 56 Kbps and no semipermanent connections for the Eng map class:
dialer string 4156884540 class Eng! This map-class ensures that these calls use an ISDN speed of 56 kbps and that! no semipermanent connection is set up.map-class dialer Engisdn speed 56Related Command
dialer string (dialer profiles)
dialer-list list
To apply an access list to a specified dialer group (and thus to specify which packets can initiate a dialed call), use the dialer-list list global configuration command. To remove a prior association between an access list and the dialer group, use the no form of this command.
dialer-list dialer-group list access-list-number
no dialer-list dialer-group list access-list-numberSyntax Description
Default
No dialer list group is defined.
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
The dialer-list list command applies access lists to dialer groups to control dialing using DDR. This command applies access lists to the dialer groups that are defined with the dialer-group command.
To specify additional protocols and access control with a finer granularity, see the dialer-list protocol command.
lists the access list types and numbers that the dialer-list list command supports.
Table 10
Standard IP
1-99
Extended IP
100-199
Transparent Bridging
200-299
Standard Novell IPX
800-899
Extended Novell IPX
900-999
Access List Numbers for the Dialer-List List Command
Examples
Dialing occurs when an interesting packet (one that matches access list specifications) needs to be output on an interface. Using the standard access list method, packets can be classified as interesting or uninteresting.
In the following example, Interior Gateway Routing Protocol (IGRP) Transmission Control Protocol/Internet Protocol (TCP/IP) routing protocol updates are not classified as interesting and do not initiate calls:
access-list 101 deny igrp 0.0.0.0 255.255.255.255 255.255.255.255 0.0.0.0The following example classifies all other IP packets as interesting and permits them to initiate calls:
access-list 101 permit ip 0.0.0.0 255.255.255.255 0.0.0.0 255.255.255.255Then the following command places list 101 into dialer access group 1:
dialer-list 1 list 101Related Commands
dialer-group
dialer-list protocoldialer-list protocol
To define a DDR dialer list to control dialing by protocol or by a combination of protocol and access list, use the dialer-list protocol global configuration command. To delete a dialer list, use the no form of this command.
dialer-list dialer-group protocol protocol-name {permit | deny | list access-list-number |
access-group}
no dialer-list dialer-group [protocol protocol-name [list access-list-number | access-group]]Syntax Description
Default
No dialer lists are defined.
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0. The list command and access-list-number and access-group arguments first appeared in Cisco IOS Release 10.3.
The various no forms of this command have the following effects:
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The dialer-list protocol form of this command permits or denies access to an entire protocol. The dialer-list protocol list form of this command provides a finer permission granularity and also supports protocols that were not previously supported.
The dialer-list protocol list form of this command applies protocol access lists to dialer access groups to control dialing using DDR. The dialer access groups are defined with the dialer-group command.
Although the dialer-list list command is still supported for IP, IPX, DECnet, AppleTalk, XNS, and bridging, the new dialer-list protocol list command should be used for all protocols. The dialer-list protocol list command is supported for all those protocols and also for Banyan VINES and International Organization for Standardization (ISO) Connectionless Network Service (CLNS).
lists the access list types and numbers that the dialer-list protocol list command supports. The table does not include ISO CLNS because that protocol uses filter names instead of predefined access list numbers.
Table 11
Dialer-List Supported Access List Types and Numbers
Examples
Dialing occurs when an interesting packet (one that matches access list specifications) needs to be output on an interface. Using the standard access list method, packets can be classified as interesting or uninteresting. In the following example, IGRP TCP/IP routing protocol updates are not classified as interesting and do not initiate calls:
access-list 101 deny igrp 0.0.0.0 255.255.255.255 255.255.255.255 0.0.0.0The following example classifies all other IP packets as interesting and permits them to initiate calls:
access-list 101 permit ip 0.0.0.0 255.255.255.255 0.0.0.0 255.255.255.255Then the following command places list 101 into dialer access group 1:
dialer-list 1 protocol ip list 101In the following example, DECnet access lists allow any DECnet packets with source area 10 and destination area 20 to trigger calls:
access-list 301 permit 10.0 0.1023 10.0 0.1023access-list 301 permit 10.0 0.1023 20.0 0.1023Then the following command places list 301 into dialer access group 1:
dialer-list 1 protocol decnet list 301In the following example, both IP and VINES access lists are defined. The IP access lists define IGRP packets as uninteresting, but permits all other IP packets to trigger calls. The VINES access lists do not allow Routing Table Protocol (RTP) routing updates to trigger calls, but allow any other data packets to trigger calls.
access-list 101 deny igrp 0.0.0.0 255.255.255.255 0.0.0.0 255.255.255.255access-list 101 permit ip 0.0.0.0 255.255.255.255 0.0.0.0 255.255.255.255!vines access-list 107 deny RTP 00000000:0000 FFFFFFFF:FFFF 00000000:0000 FFFFFFFF:FFFFvines access-list 107 permit IP 00000000:0000 FFFFFFFF:FFFF 00000000:0000 FFFFFFFF:FFFFThen the following two commands place the IP and VINES access lists into dialer access group 1:
dialer-list 1 protocol ip list 101dialer-list 1 protocol vines list 107In the following example, a Connectionless Network Service (CLNS) filter is defined and then the filter is placed in dialer access group 1:
clns filter-set ddrline permit 47.0004.0001....!dialer-list 1 protocol clns list ddrlineRelated Commands
A dagger (†) indicates that the command is documented outside this chapter.
access-list †
clns filter-set †
dialer-group
dialer-list list
vines access-list †dialer load-threshold
To configure bandwidth on demand by setting the maximum load before the dialer places another call to a destination, use the dialer load-threshold interface command. To disable the setting, use the no form of this command.
dialer load-threshold load [outbound | inbound | either]
no dialer load-threshold loadSyntax Description
Default
No maximum load is predefined.
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
This command applies to dialer rotary groups only.
When the cumulative load of all UP links(a number n) exceeds the load threshold the dialer adds an extra link and when the cumulative load of all UP links minus one (n - 1) is at or below load threshold then the dialer can bring down that one link. The dialer will make additional calls or drop links as necessary but will never interrupt an existing call to another destination.
The argument load is the calculated weighted average load value for the interface; 1 is unloaded and 255 is fully loaded. The load is calculated by the system dynamically, based on bandwidth. You must set the bandwidth for an interface in kilobits per second, using the bandwidth command.
The load calculation determines how much of the total bandwidth you are using. A load value of 255 means that you are using one hundred percent of the bandwidth. The load number is required.
See the "Interface Commands" chapter in the Configuration Fundamentals Command Reference for a full description of the bandwidth command.
When multilink PPP is configured, the dialer-load threshold 1 command no longer keeps a multilink bundle of n links connected indefinitely and the the dialer-load threshold 2 command no longer keeps a multilink bundle of 2 links connected indefinitely. If you want a multilink bundle to be connected indefinitely, you must set a very high idle timer.
Example
In the following example, if the load to a particular destination on an interface in dialer rotary group 5 exceeds interface load 200, the dialer will initiate another call to the destination:
interface dialer 5 dialer load-threshold 200Related Commands
A dagger (†) indicates that the command is documented outside this chapter.
bandwidth †
interface dialer
dialer rotary-groupdialer map
To configure a serial interface or Integrated Services Digital Network (ISDN) interface to call one or multiple sites, use a form of the dialer map interface configuration command; all options are shown in the first form of the command. To delete a particular dialer map entry, use a no form of this command.
dialer map protocol next-hop-address [name hostname] [spc] [speed 56 | 64] [broadcast]
[modem-script modem-regexp] [system-script system-regexp]
[dial-string[:isdn-subaddress]]
no dialer map protocol next-hop-address [name hostname] [spc] [speed 56 | 64] [broadcast]
[modem-script modem-regexp] [system-script system-regexp]
[dial-string[:isdn-subaddress]]To configure a serial interface or ISDN interface to place a call to multiple sites and to authenticate calls from multiple sites, use the second form of the dialer map command:
dialer map protocol next-hop-address [name hostname] [spc] [speed 56 | 64] [broadcast]
[dial-string[:isdn-subaddress]]
no dialer map protocol next-hop-address [name hostname] [spc] [speed 56 | 64] [broadcast]
[dial-string[:isdn-subaddress]]To configure a serial interface or ISDN interface to support bridging, use the third form of the command:
dialer map bridge [name hostname] [spc] [broadcast] [dial-string[:isdn-subaddress]]
no dialer map bridge [name hostname] [spc] [broadcast] [dial-string[:isdn-subaddress]]To configure an asynchronous interface to place a call to a single site that has no modem script assigned or that requires a system script, or to multiple sites on a single line, on multiple lines, or on a dialer rotary group, use the fourth form of the dialer map command:
dialer map protocol next-hop-address [name hostname] [broadcast] [modem-script
modem-regexp] [system-script system-regexp] [dial-string]
no dialer map protocol next-hop-address [name hostname] [broadcast] [modem-script
modem-regexp] [system-script system-regexp] [dial-string]Syntax Description
Defaults
No dialer map is configured. The default speed is 64 kbps. No scripts are defined for placing calls.
Command Mode
Interface configuration
Usage Guidelines for Synchronous Interfaces
This command first appeared in Cisco IOS Release 10.0.
Use the dialer map command with the name keyword in configurations in which remote sites are calling a central site, but the central site is not calling the remote site. With this command, the local device will authenticate the remote site using Challenge Handshake Authentication Protocol (CHAP) or Password Authentication Protocol (PAP), which will transmit the remote site's host name to the central site. The central site will then use this name to authenticate the caller, and will use the next hop address to transmit packets to the remote site. Because there is no dialer string specified, the central site cannot call the remote router.
Usage Guidelines for ISDN Interfaces
Use the dialer map command with the name keyword in configurations in which remote sites are calling a central site, but the central site is not calling the remote site. With this command, the local device will authenticate the remote site using CHAP or PAP, which will transmit the remote site's host name to the central site. The central site will then use this name to authenticate the caller, and will use the next hop address to transmit packets to the remote site. Because there is no dialer string specified, the central site cannot call the remote router.
For ISDN interfaces only, you can specify an optional speed parameter for dialer map commands if you also specify a dial string. This option informs the ISDN software whether it should place a call at 56 or 64 kbps. If you omit the ISDN speed parameter, the default is 64 kbps.
For routers with ISDN interfaces, if calling line identification (CLI)—also known as caller ID and ANI—is provided, the hostname field may contain the number that calling line ID provides.
Usage Guidelines for Asynchronous Interfaces
Specify chat scripts for a physical interface that is not part of a dialer rotary group if no chat script is specified for the line, or if an additional (system) chat script is required to log on to the remote system.
Configure a dialer map command for each remote destination for that interface.
You do not need to specify a system script under the following conditions:
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If you adhere to the chat script naming convention suggested in the description of the chat-script command, use the form [modem-script *modulation-type] in the dialer map command; for example, .*-v32bis. This form allows you to specify the modulation type that is best for the system you are calling, and allows the modem type for the line to be specified by the script dialer command.
The period (.) is a wildcard that matches any character, and the asterisk (*) indicates that the preceding character can be duplicated multiple times. For more information about regular expressions, see the "Regular Expressions" appendix in the Access Services Command Reference.
If a modem script is specified in the dialer map interface configuration command and a modem script specified in the script dialer line configuration command, the first chat script that matches both is used. If no script matches both, an error message is logged and the connection is not established. If there is no modem chat script specified for the line, the first chat script (that is, the one specified in the chat-script global configuration command) that matches the modem script's regular expression is used. If there is a system script specified in the dialer map interface configuration command, the first chat script to match the regular expression is used.
The modem-script and system-script keywords and corresponding arguments are optional. They are ignored on synchronous interfaces.
If you have named your chat script according to the type of modem and modulation (for example, codex-v32 or telebit v32), your regular expression could be codex-.* in the script dialer line configuration command, and *-v32bis in the modem script specified in the dialer map command for a system that you wish to connect to using V.32bis modulation.
The modem lines (specified by the argument regexp in the script dialer line configuration command) would be set to one of the following regular expressions to match patterns, depending on the kind of modem you have:
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With an interface configured for Challenge Handshake Authentication Protocol (CHAP) or Password Authentication Protocol (PAP) and configured with the name hostname keyword and argument pair, the local device authenticates the remote site using CHAP, which transmits the remote site's host name to the central site. The central site then uses this name to authenticate the caller and uses the next hop address to transmit packets to the remote site. Because no dialer string is specified, the central site cannot call the remote router.
For routers with ISDN interfaces, if calling line identification (CLI)—also known as caller ID and ANI—is provided, the hostname field can contain the number that calling line ID provides.
Examples
In the following example, the dialer speed is set at 56 kbps to call a remote site at 131.108.2.5:
interface async 1encapsulation pppppp authentication chapdialer map ip 131.108.2.5 speed 56The following example shows a dialing chat script and a login chat script. The dialer in-band command enables DDR on asynchronous interface 10, and the dialer map command looks for the specified dialing and the login scripts and then uses those scripts to dial 96837890.
chat-script dial ABORT ERROR "" "AT Z" OK "ATDT \T" TIMEOUT 30 CONNECT \cchat-script login ABORT invalid TIMEOUT 15 name: billw word: wewpass ">""slip default"interface async 10dialer in-banddialer map ip 10.55.0.1 modem-script dial system-script login 96837890In the following example, the remote site is calling the central site, and the central site is calling the remote site. The central router can use the name ZZZ to authenticate the remote router when they connect and also can use the dialer string 14155553434 to call the remote router if it is not currently connected.
interface async 1dialer map ip 131.108.2.5 name ZZZ 14155553434In the following example, a remote site is calling a central site, but the central site is not calling the remote site. The local device will authenticate the site that is calling in using CHAP. CHAP will cause the remote site's name, YYY, to be transmitted to the site it is calling. The central site will then use this name to authenticate the remote site.
interface async 1encapsulation pppppp authentication chap
