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Cisco IOS Release 12.0 Dial Solutions Command Reference
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About This Manual
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Using Cisco IOS Software
- Part 1: Dial-In Port Setup
- Part 2: Dial-In Terminal Service & Remote Node Config
- Part 3: Dial-on-Demand Routing
- Part 4: Dial Backup
- Part 5: NASI Client Commands
- Part 6: Large-Scale Dial Solutions
- Part 7: Cost-Control Solutions
- Part 8: Virtual Private Dialup Networks
- Part 9: Other Network Traffic on ISDN Channels
- Part 10: Dial-Related Addressing Services
- Part 11: Appendixes
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Index
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Table Of Contents
Modem Support and Asynchronous Commands
Modem Support and Asynchronous Commands
The configuration commands described in this chapter are used to configure modems and modem lines on access servers and routers.
Note
Some commands previously documented in this chapter have been replaced by new commands. Although these commands continue to perform their normal functions in the current release, support for these commands will cease in future releases.
For line configuration information and examples, refer to the "Configuring Modem Support and other Asynchronous Features" chapter in the Dial Solutions Configuration Guide.
async-bootp
To support the extended BOOTP request specified in RFC 1084, and to specify information that will be sent in response to BOOTP requests, use the async-bootp global configuration command. To clear the list, use the no form of this command.
async-bootp tag [:hostname] data
no async-bootp tag [:hostname] dataSyntax Description
Default
If no extended BOOTP commands are entered, the software generates a gateway and subnet mask appropriate for the local network.
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
Each of the tag keyword-argument pairs is a field that can be filled in and sent in response to BOOTP requests from clients.
BOOTP supports the extended BOOTP requests specified in RFC 1084 and works for both SLIP and PPP encapsulation.
Use the show async bootp EXEC command to list the configured parameters. BOOTP works for both SLIP and PPP.
Examples
The following example specifies different boot files: one for a PC and one for a Macintosh. With this configuration, a BOOTP request from the host on 192.168.31.1 results in a reply listing the boot filename as pcboot. A BOOTP request from the host named mac results in a reply listing the boot filename as macboot.
async-bootp bootfile :192.168.31.1 "pcboot"async-bootp bootfile :mac "macboot"The following example specifies a subnet mask of 255.255.0.0:
async-bootp subnet-mask 255.255.0.0The following example specifies a negative time offset of the local subnetwork of -3600 seconds:
async-bootp time-offset -3600The following example specifies the IP address of a time server:
async-bootp time-server 192.168.31.1Related Commands
You can use the master indexes or search online to find documentation of related commands.
service old-slip-prompts
async default ip address
The peer default ip address command replaces the async default ip address command.
Refer to the description of the peer default ip address command in the "Media Independent PPP and Multilink PPP Commands" chapter of this book for more information.
async default routing
To enable the router to pass routing updates to other routers over the AUX port configured as an asynchronous interface, use the async default routing interface configuration command. To disable dynamic addressing, use the no form of this command.
async default routing
no async default routingSyntax Description
This command has no keywords or arguments.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Use the async default routing command to define the default behavior for router-to-router communication over connections to the AUX port configured as an asynchronous interface. This command is commonly used to enable two routers to communicate over an async dial backup link.
To require a remote user to manually configure routing over connections to the AUX port configured as an asynchronous interface, use the async dynamic routing command.
Example
The following example enables routing over asynchronous interface 0:
interface async 0async default routingRelated Command
async dynamic routing
async dynamic address
To specify dynamic asynchronous addressing, use the async dynamic address interface configuration command. To disable dynamic addressing, use the no form of this command.
async dynamic address
no async dynamic addressSyntax Description
This command has no arguments or keywords.
Default
Dynamic addressing is disabled.
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
You can control whether addressing is dynamic (the user specifies the address at the EXEC level when making the connection), or whether default addressing is used (the address is forced by the system). If you specify dynamic addressing, the router must be in interactive mode and the user will enter the address at the EXEC level.
It is common to configure an asynchronous interface to have a default address and to allow dynamic addressing. With this configuration, the choice between the default address or a dynamic addressing is made by the user when they enter the slip or ppp EXEC command. If the user enters an address, it is used, and if the user enters the default keyword, the default address is used.
Example
The following example shows dynamic addressing assigned to async interface 6.
interface ethernet 0ip address 10.0.0.1 255.0.0.0interface async 6async dynamic addressRelated Commands
You can use the master indexes or search online to find documentation of related commands.
peer default ip address
async dynamic routing
To enable manually configured routing on an asynchronous interface, use the async dynamic routing interface configuration command. Use the no form of this command to disable routing protocols; static routing is still used.
async dynamic routing
no async dynamic routingSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
The async dynamic routing command is commonly used to manually bring up PPP from an EXEC session.
Example
The following example shows how to enable manually configured routing on asynchronous interface 1. The ip tcp header-compression passive command enables Van Jacobson TCP header compression and prevents transmission of compressed packets until a compressed packet arrives from the asynchronous link.
interface async 1async dynamic routing async dynamic addressasync default ip address 1.1.1.2 ip tcp header-compression passiveA remote user who establishes a PPP or SLIP connection to this asynchronous interface can enable routing by using the /routing switch or the ppp/routing command.
However, if you want to establish routing by default on connections to an asynchronous interface, use the async default routing command when you configure the interface.
Related Commands
async default routing
async dynamic address
ip tcp header-compressionautocommand
To configure the Cisco IOS software to automatically execute a command when a user connects to a particular line, use the autocommand line configuration command. Use the no form of this command to disable the automatic execution.
autocommand command
no autocommand commandSyntax Description
command
Any appropriate EXEC command, including the host name and any switches that occur with the EXEC command.
Default
No commands are configured to automatically execute.
Command Mode
Line configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
This command enables you to automatically execute an EXEC command when a user connects to a line.
Example
The following example forces an automatic connection to a host named host21 (which could be an IP address):
line vty 4 autocommand connect host21autohangup
To configure automatic line disconnect, use the autohangup line configuration command. This command causes the EXEC to issue the exit command when the last connection closes. Use the no form of this command to disable automatic line disconnect.
autohangup
no autohangupSyntax Description
This command has no arguments or keywords.
Default
Disabled
Command Mode
Line configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
This command is useful for UNIX UUCP applications that automatically disconnect lines because UUCP scripts cannot issue the exit command to hang up the telephone.
Example
The following example enables automatic line disconnect on lines 5 through 10:
line 5 10autohangupclear line
To return a terminal line to idle state, use the clear line EXEC command.
clear line line-number
Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Use this command to log out of a specific session running on another line. If the line uses a modem, the modem will be disconnected.
Example
The following example resets line 3 to idle state:
clear line 3exec
To allow an EXEC process on a line, use the exec line configuration command. Use the no form of this command to turn off the EXEC process for the specified line.
exec
no execSyntax Description
This command has no arguments or keywords.
Default
The EXEC processes start is activated automatically on all lines.
Command Mode
Line configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
When you want to allow an outgoing connection only for a line, use the no exec command. When a user tries to Telnet to a line with the no exec command configured, the user will get no response when pressing the Return key at the login screen.
Example
The following example turns off the EXEC on line 7. You might want to do this on the auxiliary port if the attached device (for example, the control port of a rack of modems) sends unsolicited data. If this happens, an EXEC process starts, which makes the line unavailable.
line 7 no execexec-timeout
To set the interval that the EXEC command interpreter waits until user input is detected, use the exec-timeout line configuration command. Use the no form of this command to remove the timeout definition.
exec-timeout minutes [seconds]
no exec-timeoutSyntax Description
minutes
Integer that specifies the number of minutes.
seconds
(Optional) Additional time intervals in seconds. An interval of zero specifies no timeouts.
Default
10 minutes
Command Mode
Line configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
If no input is detected, the EXEC facility resumes the current connection, or if no connections exist, it returns the terminal to the idle state and disconnects the incoming session. It is the same as entering exec-timeout 0.
Examples
The following example sets a time interval of 2 minutes, 30 seconds:
line console exec-timeout 2 30The following example sets a time interval of 10 seconds:
line console exec-timeout 0 10flowcontrol
To set the method of data flow control between the terminal or other serial device and the router, use the flowcontrol line configuration command. Use the no form of this command to disable flow control.
flowcontrol {none | software [lock] [in | out] | hardware [in | out]}
no flowcontrol {none | software [in | out] | hardware [in | out]}Syntax Description
Default
No flow control
Command Mode
Line configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
When software flow control is set, the default stop and start characters are Ctrl-S and Ctrl-Q (XOFF and XON). You can change them with the stop-character and start-character commands.
If a remote Telnet device requires software flow control, the remote system should not be able to turn it off. Using the lock option makes it possible to refuse "dangerous" Telnet negotiations if they are inappropriate.
Example
The following example sets hardware flow control on line 7:
line 7flowcontrol hardwareRelated Commands
You can use the master indexes or search online to find documentation of related commands.
start-character
stop-character
terminal flowcontrolgroup-range
To create a list of member asynchronous interfaces (associated with a group interface), use the group-range interface configuration command. Use the no form of the command to remove an interface from the member list.
group-range low-end-of-range high-end-of-range
no group-range interfaceSyntax Description
low-end-of-range
Beginning interface number to be made a member of the group interface.
high-end-of-range
Ending interface number to be made a member of the group interface.
Default
No interfaces are designated as members of a group.
Command Mode
Interface configuration
Usage Guidelines
Using the group-range command, you create a group of asynchronous interfaces that are associated with a group asynchronous interface on the same device. This group interface is configured by using the interface group-async command. This one-to-many structure allows you to configure all associated member interfaces by entering one command on the group interface, rather than entering this command on each interface. You can customize the configuration on a specific interface by using the member command.
Examples
The following example defines interfaces 2, 3, 4, 5, 6, and 7 as members of asynchronous group interface 0:
interface group-async 0group range 2 7Related Commands
You can use the master indexes or search online to find documentation of related commands.
interface group-async
memberhold-queue
To limit the size of the IP output queue, use the hold-queue interface configuration command. To return the output queue to the default size, use the no form of this command.
hold-queue packets
no hold-queueSyntax Description
Default
10 packets (default for asynchronous interfaces only)
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0. The no hold-queue command first appeared in Cisco IOS Release 11.1.
The default of 10 packets allows the Cisco IOS software to queue a number of back-to-back routing updates. This is the default for asynchronous interfaces only; other media types have different defaults.
The hold queue stores packets received from the network that are waiting to be sent to the client. It is recommended that the queue size not exceed ten packets on asynchronous interfaces. For most other interfaces, queue length should not exceed 100.
Example
The following example changes the packet queue length of a line to five packets:
interface async 2async default ip address 172.31.7.5hold-queue 5ip access-group
To configure an access list to be used for packets transmitted to and from the asynchronous host, use the ip access-group interface configuration command. To disable control over packets transmitted to or from an asynchronous host, use the no form of this command.
ip access-group access-list-number {in | out}
no ip access-group access-list-numberSyntax Description
Default
Disabled
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
With this command in effect, the IP destination address of each packet is run through the access list for acceptability and dropped or passed.
Example
The following example assumes that users are restricted to certain servers designated as SLIP or PPP servers, but that normal terminal users can access anything on the local network:
! access list for normal connectionsaccess-list 1 permit 172.16.0.0 0.0.255.255!! access list for SLIP packets.access-list 2 permit 172.16.42.55access-list 2 permit 172.16.111.1access-list 2 permit 172.16.55.99!! Specify the access listinterface async 6async dynamic addressip access-group 1 outip access-group 2 inip mtu
To specify the size of the largest Internet packet, use the ip mtu interface configuration command. To return to the default MTU size of 1500 bytes, use the no form of this command.
ip mtu bytes
no ip mtuSyntax Description
Default
1500 bytes
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Example
The following example sets the packet MTU size to 200 bytes:
interface async 5async default ip address 172.31.7.5ip mtu 200line
To identify a specific line for configuration and start the line configuration command collection mode, use the line global configuration command.
line [aux | console | tty | vty] line-number [ending-line-number]
Syntax Description
Default
There is no default line.
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
You can address a single line or a consecutive range of lines with the line command. A line number is necessary, though, and you will receive an error message if you forget to include it.
Entering the line command with the optional line type (AUX, CON, TTY, or VTY) designates the line number as a relative line number. For example, to configure line parameters for line 7 (a TTY line), you could enter the following:
Router(config)# line tty 7You also can enter the line command without specifying a line type. In this case, the line number is treated as an absolute line number. For example, to configure line parameters for line 5, which can be of any type, you could enter the following:
Router(config)# line 5Absolute line numbers increment consecutively and can be difficult to manage on large systems. Relative line numbers are a shorthand notation used in configuration. Internally, the Cisco IOS software uses absolute line numbers. You cannot use relative line numbers everywhere, but you can use absolute line numbers everywhere.
The absolute line number of the auxiliary port is 1. The relative line number of the auxiliary port is 0. See the modem line configuration command to set up modem support on the auxiliary port.
The software keeps a table of absolute and relative line numbers that you can display with the EXEC command show users all. A sample display follows:
Router> show users allLine User Host(s) Idle Location 0 con 0 chaff console 1 tty 1 Engineering printer 2 tty 2 3 tty 3 DREGGS 1:07 Katy x1111 4 tty 4 Console E3-D 5 tty 5 Mkt. demo area 6 tty 6 7 tty 7 DREGGS 14 Marie x1112 10 tty 10. . .135 tty 135 136 tty 136 137 tty 137 rp4-printer 140 tty 140 Braille printer 141 aux 0 142 vty 0 Denise idle DENISE-MAC.CISCO.COM 143 vty 1 Michael idle 0 DREGGS.CISCO.COM 144 vty 2 145 vty 3 146 vty 4 147 vty 5The absolute line numbers are listed at the far left, followed by the line type, and then the relative line number. Relative line numbers always begin numbering at zero and define the type of line. Addressing the second virtual terminal line as line VTY 1, for example, is easier than remembering it as line 143—its absolute line number.
The line types are ranked as follows in the line table:
1
2
3
4
5
The terminal from which you locally configure the router is attached to the console port. To configure line parameters for the console port, enter the following:
Router(config)# line con 0The console relative line number must be 0.
Virtual terminal lines are used to allow remote access to the router. A virtual terminal line is not associated with either the auxiliary or console port. The router has five virtual terminal lines by default. However, you can create additional virtual terminal lines as described in the section "Create Additional Virtual Terminal Lines" in the "Configuring Protocol Translation and Virtual Asynchronous Devices" chapter of the Dial Solutions Configuration Guide.
Configuring the console port or virtual terminal lines allows you to perform such tasks as setting communication parameters, specifying autobaud connections, and configuring terminal operating parameters for the terminal you are using.
Examples
The following example starts configuration for virtual terminal lines 0 to 4:
line vty 0 4In the following example, the user creates and configures the maximum 100 virtual terminal lines with the no login command:
line vty 0 99no loginIn the following example, the user eliminates virtual terminal line number 5 and all higher-numbered virtual terminal lines. Only virtual terminal lines 0 to 4 will remain.
no line vty 5In the following example, the user configures console line 0, auxiliary line 0, and virtual terminal lines 0 to 4:
line vty 0 4loginline con 0password baskervilleline aux 0password Mypasswordno execaccess-class 1 inspeed 19200line vty 0exec-timeout 0 0password Mypasswordline vty 1exec-timeout 0 0password Mypasswordline vty 2exec-timeout 0 0password Mypasswordline vty 3password Mypasswordline vty 4password MypasswordRelated Commands
You can use the master indexes or search online to find documentation of related commands.
show line
show users allmember
To alter the configuration of an asynchronous interface that is a member of a group, use the member interface configuration command. Use the no form of the command to restore defaults set at the group master interface.
member number interface-command
no member number interface-commandSyntax Description
number
Number of the asynchronous interface to be altered.
interface-command
One or more of the following commands entered for this specific interface:
•
•
Default
No individual configurations are set for member interfaces.
Command Mode
Interface configuration
Usage Guidelines
You can customize a member interface by using the member command. (Interfaces are designated as members of a group by using the interface group-async and group-range commands.) To restore the defaults set at the group master interface, use the no form of this command.
Examples
The following example defines interface 3 with a description of line 3, which is attached to a Hayes Optima modem:
interface group-async 0 member 3 description line #3 Hayes OptimaRelated Commands
You can use the master indexes or search online to find documentation of related commands.
group-range
interface group-asyncmodem call-record
To activate the logging of a summary of modem events upon the termination of a call, use the modem call-record command in global configuration mode. Use the no form of this command to deactivate modem event logging of calls.
modem call-record terse
no modem call-recordSyntax Description
Default
Logging of modem events is off.
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3(6) AA.
The modem management subsytem provides event logs for each modem at each major event during usage of the modems. The volume of event logs being generated make the monitoring of modem calls for debugging purposes difficult. MCR log, activated using the modem call-record command, will log a summary of a modem call to syslog upon termination of the call. If a call fails to establish a connection, the call will be summarized in a Modem Call Failed Record.
The MCR is written to the syslog and can be displayed using the terminal monitor or show logging command, or by examining files on a syslog server.
The modem call-record command is supported on routers with integrated MICA technologies and Microcom modems.
The information provided in the MCR log and the Modem Call Failed Record log varies depending on the type of modem being used. The following table describes the significant fields in the display for MICA and Microcom modems.
Table 2 modem call-record Field Descriptions
Interface slot
Interface slot of device assigned for call.
Interface controller unit
Interface controller unit of device assigned for call.
Interface channel
Interface channel of device assigned for call.
Modem type
Modem type used for call.
Modem slot/port
Physical location for modem handling the call.
Call id
Unique Call Identifier assigned to the modem call by the call switching module.
Userid
User ID of caller.
IP address
IP address assigned for caller.
Calling number
Modem calling number.
Called number
Modem called number.
Connected standard
Standard used for connection. Possible values are Bell103, Bell212, K56Flex 1.1, V.17, V.21, V.22, V.22bis, V.23, V.27, V.29, V.32, V.32bis, V.32terbo. V.34, V.34+, and V.90.
Connect protocol
Protocol user for connection. Possible values are ARA1.0, ARA2.0, ASYNC Mode, FAX Mode, LAP-M, MNP, SS7/COT, and SYNC Mode.
Compression
Compression method used for connection. Possible values are MNP5 data, none, V.42bis both, V.42bis RX, and V.42bis TX.
Initial RX bit rate
Actual bit rate from the remote Digital Signal Processor (DSP) to the local DSP at connect.
Initial TX bit rate
Actual bit rate from the local DSP to the remote DSP at connect.
Final RX bit rate
Actual bit rate from the remote DSP to the local DSP at disconnect.
Final TX bit rate
Actual bit rate from the local DSP to the remote DSP at disconnect.
RBS pattern1
Actual Robbed Bit Signaling (RBS) pattern observed by the modem. The six LSBs of the returned value indicate the periodic RBS pattern where a one denotes a pulse code modulation sample with a robbed-bit. (Only reported for K56Flex).
Digital pad1
Amount of digital padding (attenuation) in downlink, in decibles. (Only reported for V.90 and K56Flex.)
Total retrains1
Count of total retrains and speed shifts.
Signal quality value1
This value ranges from 0 to 7, where 0 is the worst. The units are arbitrary, approximating abs(log10(SNR)).
SNR
Signal-to-noise ratio, ranging from 0 to 70 in dB steps.
Characters received
Count of total characters received for SYNC/ASYNC connection.
Characters transmitted
Count of total characters sent for SYNC/ASYNC connection.
Characters received BAD1
Total number of parity errored characters received (for ASYNC connections).
Error correction frames received OK
Count of error-free Error Correction frames received. Incorrect or duplicate frames are not included.
Error correction frames transmitted
Count of unique Error Correction frames sent. Re-sent frames are not included.
Error correction frames received BAD/ABORTED1
Total error correction retransmissions requested by this modem during the course of the link.
Call timer
Duration of call, in seconds.
Final state
State of modem call before it terminated.
Disconnect reason
Reason for call being disconnected. Each modem type handles parameter differently.
1 These fields are displayed only for MICA modems.
Example
The following example shows the activation of MCR logging:
modem call-record terseThe following is the MCR of a successful call on a MICA modem:
*Aug 15 01:34:08.775: %CALLRECORD-3-MICA_TERSE_CALL_REC:DS0 slot/contr/channel=1/0/22 modem=mica slot/port=1/2 call_id=0x3userid=jdoe ip=124.34.45.120calling=#4085551212 called=#4085552222std=V.34+ prot=LAP-M comp=Noneinit-rx/tx b-rate=31200/33600 finl-rx/tx b-rate=33600/33600rbs=0 d-pad=None retr=2 sq=2 snr=28rx/tx chars=1067/0 bad=0 rx/tx ec=0/0 bad=0time=139 finl-state=Steadydisc=0xA220Type (=5 ): Rx (line to host) data flushing, not OKClass (=2 ): EC condition, locally detectedReason (=32): received DISC frame -- normal LAPM terminationThe following is the MCR of a failed call on a MICA modem:
*Aug 15 16:47:54.527: %CALLRECORD-3-MICA_TERSE_CALL_FAILED_REC:DS0 slot/contr/channel=1/0/22 modem=mica slot/port=1/2 call_id=0x9calling=4085551212# called=#4085552222time=2 finl-state=Linkdisc=0x7F06Type (=3 ): Condition occurred during call setupClass (=31): Requested by hostReason (=6 ): network indicated disconnectThe following is the MCR of a successful call on a Microcom modem:
01:17:30: %CALLRECORD-3-MCOM_TERSE_CALL_REC:DS0 slot/contr/channel=0/0/22 modem=microcom_server slot/port=0/2 call_id=0x3userid=sque ip=124.34.46.111calling=#4085551111 called=#4085552222std=V34 prot=Normal comp=NoneInit-RX/TX b-rate=33600/31200 Finl-RX/TX b-rate=33600/33600SNR=47RX/TX chars=0/0 RX/TX EC=0/0time=73 Disc(local)=0x9 DTR Drop Disc(remote)=0x0 UnknownThe following is the MCR of a failed call on a Microcom modem:
Microcom Terse Modem Call Failed Record Log:19:28:55: %CALLRECORD-3-MCOM_TERSE_CALL_FAILED_REC:DS0 slot/contr/channel=0/0/0 modem=microcom_server slot/port=0/2 call_id=0xA003calling=4085551111# called=#4085552222time=0 finl-state=Dialing/Answeringdisc(local)=0x9 DTR Drop disc(remote)=0x0 UnknownRelated Commands
You can use the master indexes or search online to find documentation of related commands.
show logging
terminal monitormodem callin
To support dial-in modems that use the data terminal ready (DTR) signal to control the off-hook status of the modem, use the modem callin line configuration command. Use the no form of this command to disable this feature.
modem callin
no modem callinSyntax Description
This command has no arguments or keywords.
Default
No modem control
Command Mode
Line configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
In response to RING, the router raises the DTR signal, which indicates to the modem that it should answer the call. At the end of the session, the Cisco IOS software lowers DTR, which disconnects the modem. This command is useful for older modems that do not support auto answer.
This command uses CTS, whereas newer modem commands in the Cisco IOS software use DSR.
Only use the modem callin command on the ASM terminal server, where hardware flow control is not possible. If you have a more recent device (such as a Cisco 2509 through 2512, Cisco 2520 through 2523, a Cisco AS5100, Cisco 3600 series, or Cisco AS5200), use the modem dialin command instead.
Example
The following example configures lines 10 through 16 for dial-in modems that can run at speeds from 300 to 19,200 bps:
line 10 16 modem callin autobaudRelated Commands
You can use the master indexes or search online to find documentation of related commands.
modem answer-timeout
modem inoutmodem callout
To configure a line for reverse connections, use the modem callout line configuration command. Use the no form of this command to disable this feature.
modem callout
no modem calloutSyntax Description
This command has no arguments or keywords.
Default
No modem control
Command Mode
Line configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
This command supports ports connected to computers that would normally be connected to modems. It causes the access server to act somewhat like a modem.
This command uses CTS and should be used only on access servers that do not support hardware flow control. If you have an access server that is newer than the ASM terminal server (such as a Cisco 2509 through 2512, Cisco 2520 through 2523, a Cisco AS5100, Cisco 3600 series, or a Cisco AS5200), use the modem host command instead. The modem callout command uses CTS, whereas the modem host command uses DSR/DCD. If CTS is used for modem control instead of DSR/DCD, it prevents CTS from being used by hardware flow control.
Example
The following example configures lines 17 through 32 in reverse connection mode to a large terminal switch. By using Telnet to connect to a TCP port on this host, the user gets the next free line in the rotary group.
line 17 32 rotary 1 modem calloutRelated Commands
You can use the master indexes or search online to find documentation of related commands.
modem inout
:rotarymodem cts-required
The modem printer command replaces the modem cts-required command. Refer to the description of the modem printer command for more information.
modem dialin
To configure a line to enable a modem attached to the router to accept incoming calls only, use the modem dialin line configuration command. Use the no form of this command to disable this feature.
modem dialin
no modem dialinSyntax Description
This command has no arguments or keywords.
Default
Do not permit incoming calls to the modem.
Command Mode
Line configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.1.
This command supports modems that can automatically handle telephone line activity, such as answering the telephone after a certain number of rings.
Example
The following example configures a line for a high-speed modem:
line 5 modem dialinRelated Commands
You can use the master indexes or search online to find documentation of related commands.
dialer
modem inout
paritymodem dtr-active
To configure a line to leave data terminal ready (DTR) signals low, unless the line has an active incoming connection or an EXEC process, use the modem dtr-active line configuration command. Use the no form of this command to disable this feature.
modem dtr-active
no modem dtr-activeSyntax Description
This command has no arguments or keywords.
Default
No modem control
Command Mode
Line configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
This command does not use the Carrier Detect (CD) signal.
This command can be useful if the line is connected to an external device (for example, a time-sharing system) that must know whether a line is in active use. The modem dtr-active command is similar to the no modem line configuration command.
Example
The following example configures a line for low DTR:
line 5 modem dtr-activeRelated Commands
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