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Managing Modems

Managing Modems

The Cisco IOS software provides commands that manage modems that reside inside access servers or routers in the form of modem cards. Cisco Systems does not consider external modems, which externally attach to an access server, to be part of its modem management paradigm.

For a complete description of the commands in this chapter, refer to the "Modem Management Commands" chapter of the Dial Solutions Command Reference. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online.

This chapter consists of the following sections:

Cisco's Implementation

Cisco Systems installs the following different types of modems and terminal adapter cards in its access servers and routers:

Table 7 shows which Cisco access devices provide hardware support for these dial technologies.


Table 7:
Type of Modem
or Terminal Adapter
Cisco  AccessPath Integrated Access System Cisco AS5300 Cisco AS5200 Cisco 3600 Series

56K modem card

Yes

Yes

Yes

Yes

V.110 terminal adapter module

No

No

Yes

No

V.34 modem card

Yes

Yes

Yes

Yes

Available Modems and Terminal Adapters

56K Modems

The 56K modems are used for making high-speed connections across digital networks. Ultimately, this means that files transmitted at up to 56 kbps arrive at the desktop nearly twice as fast as standard V.34 (28.8-kbps) connections. The wait for information is reduced by nearly 50 percent.

The 56K modems are ideal for serious Internet multimedia users who want to quickly dial-in to corporate LANs or download web pages containing sound, video, graphics, and other large files over digital networks using standard telephone lines.

Traditional modems assume that both ends of a modem conversation use an analog connection over the public switched telephone network. Data signals are converted from digital to analog and back again to digital, limiting transmission speeds to considerably less than the nominal rate of the modem. The 56K modems, however, assume that one end of the modem conversation has a pure digital connection to the phone network and takes advantage of the high-speed digital connection. This is a new technique where the network is viewed as a digital transmission medium and the data is encoded for transmission over an end user's telephone line, which is also known as the local loop. The downstream data is digitally encoded instead of being modulated. Upstream analog-to-digital communication at the local loop will be less than 56kbps. (This limit to upstream analog modem speed can vary depending on factors such as the local loop connection with the central office and the modem. Downstream digital to analog communication at the local loop can transmit up to 56 kbps. To maximize channel bandwidth for 56 kbps connections, the Integrated Services Digital Network Primary Rate Interface (ISDN PRI) must be used. In the example shown in Figure 29, a stack of Cisco  AS5300s is equipped with 56K modems.)


Figure 29: Remote PC Downloading Files Over the Network at 56 kbps

Special digital signal processor (DSP) software is used in conjunction with 56K modem firmware to enable speeds up to 56 kbps. Both DSP and modem firmware are posted on the Cisco Connection Online (CCO) FTP server for upgrading purposes.

The following prerequisites apply to 56K modems:

V.110 Terminal Adapters

V.110 is a bit rate adaptation protocol defined by International Telecommunication Union (ITU). V.110 provides a standard method of encapsulating data over Global System for Mobile Telecommunications (GSM) and ISDN networks. A Cisco AS5200 loaded with V.110 terminal adapter modules provides corporate or Internet access to GSM mobile users.

The 12 port V.110 terminal adapter connects to the AS5200 TDM bus via the universal carrier card. There can be up to five V.110 modules in one Cisco AS5200, which is capable of terminating 60 V.110 sessions. Modem and V.110 terminal adapter port modules can coexist in the same Cisco  AS5200. Based on ISDN Q.931 call bearer information, the Cisco IOS software routes calls to the appropriate port module for termination. For example, analog calls are terminated by the modem modules, GSM calls are serviced by the V.110 terminal adapter modules, and ISDN calls are sent to the PPP termination engine. This flexibility allows providing one telephone number to users for analog, GSM, and ISDN data calls.

Figure 30 shows a dial-in scenario for how V.110 technology can be used with a stack of Cisco AS5200 access servers.


Figure 30: V.110 Dial-In Scenario Using a Stack of Cisco AS5200s


V.34 Modems

Recommendation V.34 is the name of the standard that defines how modems should operate at 28.8  kbps. The previous standard for high speed modem communication was V.32bis, which defined how modems should operate at 14.4 kbps.

Manageable Versus Basic Modems

Depending on which modem license you purchase with your access server or router, Cisco modems are either manageable by the Cisco IOS software do not support the out-of-band management feature. The latter are called "basic" modems.

Manageable modems support the one out-of-band feature, which is used for gathering modem performance statistics and transmitting attention (AT) commands. Basic modems do not support the out-of-band feature nor the functionality associated with manageable modems. As you read through this chapter, note which commands apply to manageable versus basic modems.

Table 8 provides a summary of the Cisco IOS commands supported by manageable modems versus basic modems.


Table 8: Commands for Manageable versus Basic Modems
Modem Command Supported by Manageable Modems Supported by Basic Modems

called-number

Yes

Yes

clear counters (async)

Yes

Yes

clear counters line

Yes

Yes

clear modem

Yes

Yes

clear modem counters

Yes

Yes

clear modempool-counters

Yes

Yes

copy modem

Yes

Yes

modem answer-timeout

Yes

Yes

modem at-mode

Yes

No

modem at-mode-permit

Yes

No

modem autoconfigure discovery

Yes

Yes

modem autoconfigure type

Yes

Yes

modem autotest

Yes

Yes

modem bad

Yes

Yes

modem buffer-size

Yes

No

modem busyout

Yes

Yes

modem country mica

Yes

Yes

modem country microcom_hdms

Yes

Yes

modem hold-reset

Yes

Yes

modem poll retry

Yes

No

modem poll time

Yes

No

modem recovery

Yes

Yes

modem recovery-time

Yes

No

modem shutdown

Yes

Yes

modem startup-test

Yes

Yes

modem status-poll

Yes

No

modemcap edit

Yes

Yes

modemcap entry

Yes

Yes

modem-pool

Yes

Yes

pool-range

Yes

Yes

show modem

Yes

Yes

show modem at-mode

Yes

No

show modem call-stats

Yes

No

show modem configuration

Yes

No

show modem connect-speeds

Yes

No

show modem cookie

Yes

Yes

show modem csm

Yes

Yes

show modem log

Yes

Yes

show modem mapping

Yes

Yes

show modem mica

Yes

Yes

show modem operational-status

Yes

No

show modem summary

Yes

Yes

show modem test

Yes

Yes

show modem version

Yes

Yes

show modem-pool

Yes

Yes

test modem back-to-back

Yes

Yes

Modem Management Topologies

Figure 31 shows a typical small scale dial scenario for an Internet service provider. Modem management commands are useful for gathering call statistics and upgrading modem firmware for large modem pools.


Figure 31: Small-Scale POP Using a Cisco AS3640 Access Server


Figure 32 shows a large scale dial scenario for an Internet service provider extending over several states in the USA.


Figure 32: Large-Scale POP Network


Figure 33 shows a typical dial scenario for an enterprise network using a Cisco 3640 router.


Figure 33: Typical Dial Scenario for an Enterprise Network


Single Chassis Modem Pooling

Modem pooling assigns physical modems to a single dialed number identification service number (DNIS). It enables you to create pools of physical modems in one access server, assign a unique DNIS to each modem pool, and set maximum simultaneous connect limits.

This feature is used for physically partitioning or virtually partitioning modems inside one network access server. Modem pooling offers these benefits:

The following subsections are provided:

List of Terms

DNIS---Dialed number identification service number. The same DNIS cannot exist in more than one modem pool. Each modem pool must have its own unique DNIS number(s).

Called party number---DNIS number used to dial into an access server. For example, suppose Modem ABC is dialing into Access Server DEF. The DNIS called party number is the number assigned to Access Server DEF.

Calling party number---Telephone number assigned to a calling device. For example, suppose Modem ABC is dialing into Access Server DEF. The calling party number is the number assigned to Modem ABC. Calling party number is similar to Caller ID.

Modem pool---A range of physical modems that are grouped together and assigned one or more DNIS.

Restrictions

The following restrictions apply:

If you see many call failures appearing on the access server, try assigning more modems to the default pool. Use the show modem and show modem summary EXEC commands to view the modem call failure and success ratio.

Platforms Supported

Modem pooling is supported on the following access servers:

How It Works

Modem pooling allows you to control which modem a call connects to, based on DNIS. Without using modem pooling, incoming and outgoing calls are arbitrarily assigned to modems. For example, consider a Cisco AS5300 loaded with a 4-port ISDN PRI card. After an analog modem call comes into the first PRI trunk, the call is greeted by a general pool of B channels and a general pool of modems. Any B channel can be connected to any modem in the access server. A random assignment takes place. Modem resources cannot be controlled.

You can either physically partition or virtually partition your modems to enable different dial-in and dial-out services.

Configure Modem Pooling

You must first decide to physically partition or virtually partition your modems. For more information, see the previous subsection. After you have made this decision, create a modem pool for a dial-in service or specific customer by performing the tasks in the following table, beginning in EXEC configuration mode.

Step Command Purpose

1 . 

configure terminal

Access global configuration mode.

2 . 

modem-pool name

Create a modem pool, and assign it a name.

3 . 

pool-range number-number

Assign a range of modems to the pool. A dash (-) is required between the two numbers.

4 . 

called-number number [max-conn number]

Assigns the DNIS to be used for this modem pool.

The max-conn option specifies the maximum number of simultaneous connections allowed for this DNIS. If you do not specify a max-conn value, the default (total number of modems in the pool) is used.1

5 . 

Ctrl Z

Return to EXEC mode.

6 . 

show configuration

Display the running configuration to verify the modem pool settings. Make changes accordingly.

7 . 

copy running-config startup-config

Save the running configuration to the start-up configuration.

1The DNIS string can have an integer x to indicate a don't care digit for that position. For example, 555111x.


Note If you have active modem calls on the access server prior to using modem pooling, modem pooling gracefully applies itself to the access server. Modem pooling first waits for active calls to hang up before assigning modems to modem pools and directing calls according to DNIS.

Verify Modem Configuration

To verify the modem configuration, enter the show modem-pool command to view the configuration. This command shows you the structure and activity status for all the modem pools in the access server. See Table 9 for a description of each display field.

as5300# show modem-pool
modem-pool: System-def-Mpool
modems in pool: 0     active conn: 0
0 no free modems in pool
modem-pool: v90service
modems in pool: 48    active conn: 46
 8 no free modems in pool
 called_party_number: 1234
   max conn allowed: 48, active conn: 46
   8 max-conn exceeded, 8 no free modems in pool
modem-pool: v34service
modems in pool: 48    active conn: 35
 0 no free modems in pool
 called_party_number: 5678
   max conn allowed: 48, active conn: 35
   0 max-conn exceeded, 0 no free modems in pool


Table 9: Show Modem-Pool Field Descriptions
Field Description

modem-pool

Name of the modem pool. In the previous example, there are three modem pools configured: System-def-Mpool, v34service, and v90service. To set modem pool name, see the modem-pool command.

All the modems not assigned to a modem pool are automatically assigned to the system default pool (displayed as System-def-Mpool).

modems in pool

Number of modems assigned to the modem pool. To assign modems to a pool, see the pool-range command.

active conn

Number of simultaneous active connections for the specified modem pool or called party DNIS number.

no free modems in pool

Number of times incoming calls were rejected because there were no more free modems in the pool to accept the call.

called_party_number

Specified called party DNIS number. This is the number that the remote clients use to dial in to the access server. You can have more than one DNIS number per modem pool. To set the DNIS number, see the called-number command.

max conn allowed

Maximum number of modems that a called party DNIS number can use, which is an overflow protection measure. To set this feature, see the called-number command.

max-conn exceeded

Number of times an incoming call using this called party DNIS number was rejected because the max-conn number parameter specified by the called-number command was exceeded.

For modem pool configuration examples, see the section "Physical Partition with Dial-In and Dial-Out Scenario."

Check the following if you are having trouble:


Note Modem pools using MICA or Microcom modems support incoming analog calls over ISDN  PRI. However, only MICA modems support modem pooling for T1 and E1 configurations with channel associated signaling.

Physical Partitioning Scenario

Physical partitioning uses one access server to function as multiple access servers loaded with different types of modem services (for example, V.34 modems, fax-capable modems, and point-of-sale (POS) modems). Each modem service is part of one physical modem pool and is assigned a unique DNIS number. See Figure 34.


Figure 34: Modem Pooling Using Physical Partitioning


Physical partitioning can also be used to set up an access server for bidirectional dial access. See Figure 35.

Figure 35 shows one Cisco AS5300 loaded with 96 MICA modems and configured with two modem pools. One modem pool has 84 modems and collects DNIS. This pool is shared by 400 salespeople who remotely download e-mail from headquarters. The other modem pool contains 12 fax-capable modems and does not collect DNIS. This pool is shared by 40 employees using PCs on a LAN. Each time an outbound call is initiated by a PC, a modem on the Cisco AS5300 is seized and used to fax out or dial out. Not configuring DNIS support in the fax-out modem pool protects the pool from being used by the calls coming in from the field. Regardless of how many salespeople are dialing in or which telephone number they use, the fax-out/dial-out modem pool will always be reserved for the PCs connected to the LAN.

Physical Partition Example

The following example creates one V.34 modem pool and one 56K modem pool on a Cisco  AS5200. Each modem pool is configured with its own DNIS. Depending on which DNIS the remote clients dial, they connect to a V.34 Microcom modem or a 56K MICA modem.

The following hardware configuration is used on the Cisco AS5200:

Complete the following steps to configure basic physical partitioning:

Step 1 Enter global configuration mode:

Step 2 Create modem pool for the 56K MICA modem services using the modem-pool name command. The modem pool is called 56kservices, which spans across four 6-port MICA 56K modem modules.

Step 3 Assign a range of modems to the modem pool using the pool-range number-number command. Because all the 56K MICA modems are seated in slot 1, they are assigned TTY line numbers 1 to 24. Use the show line EXEC command to determine the TTY line numbering scheme for your access server.

Step 4 Assign a DNIS to the modem pool using the called-number number [max-conn number] command. This example uses the DNIS 5551111 to connect to the 56K modems. The maximum simultaneous connection limit is set to 24. The 25th user dialing 5551111 gets a busy signal.

Step 5 Return to EXEC mode by pressing CTRL Z. After you do this, display the modem pool configuration with the show modem-pool command. In this example, the 56K modems are in the modem pool called 56kservices. The remaining 24 v.34 Microcom modems are still in the default system pool.

Step 6 Create the modem pool for the Microcom physical partition. After the configuration is complete, the show modem-pool command shows that there are no remaining modems in the system default modem pool.

Physical Partition with Dial-In and Dial-Out Scenario

The following example is for a bidirectional dial scenario using a Cisco AS5300. Two modem pools are configured. One modem pool contains 84 56K MICA modems, which is shared by 400 remote salespeople dialing in to headquarters. The other modem pool contains 12 fax-capable modems, which is shared by 40 employees dialing out of the headquarters LAN using the Cisco  DialOut Utility software. See Figure 35 for the network topology.


Figure 35: Modem Pooling Used for Bidirectional Dialing


The following hardware configuration is used on the Cisco AS5300:

Complete the following steps to configure physical partitioning with dial-in and dial-out capability:

Step 1 Create the 56K modem pool for the 400 remote salespeople. This modem pool contains 84 modems, which are reserved for the dial-in calls. To get access, the salespeople dial the DNIS 5553333. The total number of simultaneous calls is limited to 84. The 85th call and above is rejected. The modem dialin line configuration command is used to prevent modems 1  to  84 from dialing out.

Step 2 Create the dial-out/ fax-out modem pool for the 40 local employees connected to the headquarters LAN. This modem pool contains 12 fax-capable MICA modems. No DNIS is assigned to the pool. Because lines 85 to 96 are used for the fax-out/ dial-out modem services, the async lines are configured for reverse telnet. This is needed for the telnet extensions to work with the dial-out application, which is installed on the LAN PCs.

Step 3 Configure the group asynchronous interface, which assigns core protocol characteristics to all the asynchronous interfaces in the system. Regardless of the direction that the modems are dialing, all modems in the access server leverage this group asynchronous configuration.

Step 4 Create an IP address pool for all the dial-in clients and dial-out clients. Both types of clients borrow addresses from this shared pool.

Step 5 (Optional) If you are using CiscoSecure AAA and a remote TACACS server, the following security statements must be included on the access server:

You should also include the host name, timeout interval, and authentication key:

Virtual Partitioning Scenario

Virtual partitioning creates one large modem pool on one access server, but assigns different DNIS numbers to different customers. Each incoming DNIS consumes resources from the same modem pool, but a maximum connect option is set for each DNIS.

Figure 36 shows two ISP customers leasing modems from another service provider. Each ISP is assigned its own DNIS number and range of modems. Each ISP is guaranteed a certain number of physical modem ports for simultaneous connections. After an ISP uses up all the modems assigned to its DNIS, a busy signal is issued.


Figure 36:
Modem Pooling Using Virtual Partitioning


Virtual partitioning essentially resells modem banks to customers, such as a small size ISP. However, keep in mind that modem pooling is a single chassis solution, not a multichassis solution. Modem pooling is not a solution for reselling ports on a large scale basis.

Virtual Partition Example

The following example creates one modem pool on a Cisco AS5300 for two ISP customers. The  shared modem pool is called isp56kpool. However, both ISP customers are assigned different DNIS numbers and limited to a maximum number of simultaneous connections.

See Figure 36 for the network topology.

The following hardware configuration is used on the Cisco AS5300:

Perform the following steps to configure virtual partitioning:

Step 1 Enter global configuration mode:

Step 2 Create the shared modem pool for the 56K MICA modem services. This modem pool is called isp56kpool, which spans across sixteen 6-port MICA 56K modem modules.

Step 3 Assign all the modems to the modem pool using the pool-range number-number command. Use the show line EXEC command to determine your TTY line numbering scheme.

Step 4 Assign a unique DNIS to each ISP customer using the called-number number [max-conn number] command. In this example, the max-conn number option limits each ISP to 48 simultaneous connections. The 49th user to dial either DNIS will get busy signal.

Step 5 Return to EXEC mode by pressing CTRL Z. After you do this, display the modem pool configuration with the show modem-pool command. In this example, all the 56K modems are in the isp56kpool modem pool. The output also shows two DNIS numbers configured: 5551111 and 5552222.

Change Modem Configuration

You can automatically change the running configuration for external modems (not embedded in modem cards) by issuing a single command. Additionally, you can change an integrated modem's running configuration by sending individual AT commands:

Changing Automatically for Externally Attached Modems

The Cisco IOS software can issue initialization strings automatically for most types of modems externally attached to an access server. A modem initialization string is a series of parameter settings that are sent to your modem to configure it to interact with the access server in a specified way. The Cisco  IOS software defines seven initialization strings that have been found to properly initialize most modems so that the modems function properly with Cisco access servers. These initialization strings have the following names:


Note Internal or integrated modems, such as those used by the Cisco AS5200 and Cisco  AS5300, are preconfigured by Cisco  Systems and do not need to be initialized.

If you do not know which of these modem strings is appropriate for your modems, issue the modem autoconfigure discovery line configuration command, as shown in the following example:

2511# configure terminal 
2511(config)# line 1 16
2511(config-line)# modem autoconfigure discovery
2511(config-line)# Ctrl-Z
2511# copy running-config startup-config

The Cisco IOS software first tries the first of these strings to see if the modem initializes properly. If not, the Cisco IOS software cycles to the next string and repeats the process until the appropriate string is found. If none of the strings properly initializes the modem, you must manually configure the modem.

If you know that your modem can be configured using an initialization string from one of these scripts, you can issue the modem autoconfigure type type command, where type is one of the strings in the preceding list. If you list a specific modem type, initialization proceeds more quickly.

To display the list of modems for which the router has modem string entries, issue the show modemcap command. You can change a modem value that was returned from the show modemcap EXEC command. For example, you might want to add the factory default, &F, entry to the configuration file. To do this, enter the modemcap edit modem-name attribute value line configuration command. Configure one attribute of one modem at a time.

The following example shows how to enter line configuration mode and issue the modem autoconfigure type type command for a US Robotics Sportster modem.

2511(config-line)# modem autoconfigure type usr_sportster

For more information about the recommended strings for any type of modem, refer to the section "Sample Modem Strings" in the appendix "Configuring Modem Support and Chat  Scripts" in the Dial Solutions Command Reference. If you have access to Cisco Connection Online (CCO), you can also access the following URL for more information (which is subject to change without notice):

http://www.cisco.com/warp/customer/76/4.html

Changing Manually by Sending AT Commands to Integrated Modems

Manageable Microcom modems have an out-of-band feature, which is used to poll modem statistics and transmit AT commands. The Cisco  IOS software uses a direct connect session to transfer information through this out-of-band feature. To send AT commands to a Microcom modem, you must permit a direct connect session for a specified modem, open a direct connect session, send AT commands to a modem, and clear the directly connected session from the modem when you are finished.


Note This sections does not describe how to send AT commands to MICA digital modems. If your system uses MICA modems, refer to the publication AT Command Set and Register Summary for MICA Six-Port Modules.

Open a direct connect session by issuing the modem at-mode slot/port command in Privileged EXEC mode. From here, you can transmit AT commands directly from your terminal session window to the internal Microcom modems. Most incoming or outgoing calls on the modems are not interrupted when you open a direct connect session and transmit AT commands. However, some AT commands interrupt a call---for example, the ATH command, which hangs up a call. Open and close one direct connect session at a time. Beware that multiple open sessions slow down modem performance.

Refer to the AT command set that came with your router for a complete list of AT commands that you can transmit to the modems.

For Microcom modems, you can clear or terminate an active directly connected session in two ways:

Transmit AT Command Example

The following example opens a directly connected session on modem 1/1, enters AT command mode on modem 1/1, and transmits the at%v and at\s commands via the out-of-band feature on modem  1/1:

router# modem at-mode 1/1
You are now entering AT command mode on modem (slot 1 / port 1).
Please type CTRL-C to exit AT command mode.
at%v
 
MNP Class 10 V.34/V.FC Modem Rev 1.0/85
 
OK
at\s
 
IDLE           000:00:00
LAST DIAL      
 
NET ADDR:      FFFFFFFFFFFF
MODEM HW: SA 2W United States
4 RTS 5 CTS 6 DSR - CD 20 DTR - RI 
MODULATION     IDLE
MODEM BPS      28800  AT%G0   
MODEM FLOW     OFF    AT\G0
MODEM MODE     AUT    AT\N3
V.23 OPR.      OFF    AT%F0
AUTO ANS.      ON     ATS0=1
SERIAL BPS     115200 AT%U0   
BPS ADJUST     OFF    AT\J0
SPT BPS ADJ.   0      AT\W0
ANSWER MESSGS  ON     ATQ0   
SERIAL FLOW    BHW    AT\Q3
PASS XON/XOFF  OFF    AT\X0
PARITY         8N     AT

The manageable modem returns "OK" if the AT command you transmit is successfully enabled.

Clear a Direct Connect Session from a Second Telnet Session Example

The following examples are for Microcom modems.

The following example shows how to execute the modem at-mode command from a Telnet session:

router# modem at-mode 1/1

The following example shows how to execute the clear modem at-mode command from a second Telnet session while the first Telnet session is connected to the modem:

router# clear modem at-mode 1/1
clear "modem at-mode" for modem 1/1 [confirm] <press Return>
router#

The following output is displayed in the first Telnet session after the modem is cleared by the second Telnet session:

Direct connect session cleared by vty0 (171.69.1.164)

Verify Connection Speed Performance

Making sure that your modems are connecting at the correct connection speeds is an important aspect of managing modems. To display modem connection speed statistics for a specific modem or range of modems, use the following EXEC commands:
Step Command Purpose

1 . 

show modem connect-speeds [max-speed [slot]]

Displays connection speed statistics for all the modems.

2 . 

show modem [slot/port | group number]

Displays a high-level performance report for all the modems or a single modem.You must type in the forward slash.

These commands also provide performance information to investigate possible bad or corrupt modems or T1/E1 lines. For example, suppose you have an access server that is fully populated with V.34 modems. If you notice that modem 1/0 is only getting V.34 connections 50% of the time, whereas all the other modems are getting V.34 connections 80% of the time, then modem 1/0 is probably malfunctioning or bad. If you are reading low connection speeds across all the modems, you may have a faulty channelized T1 or ISDN PRI line connection.

To display connection speed information for all modems running in your system, use the show modem connect-speeds max-speed EXEC command. Because most terminal screens are not wide enough to display the entire range of connection speeds at one time (for example, 75 to 56000 bps), the max-speed variable is used. This variable specifies the contents of a shifting baud-rate window, which provides you with a snap shot of the modem connection speeds for your system. Replace the max-speed argument with the maximum connect speed that you want to view. You can specify from 12000 to 56000 bps. If you are interested in viewing a snap shot of lower baud rates, specify a lower connection speed. If you are interested in viewing a snap shot of higher baud rates, specify a higher connection speed.

See the chapter "Modem Management Commands" in the Dial Solutions Command Reference for a complete description of each of the fields displayed in the following Microcom modem example:

router# show modem connect-speeds 33600
  transmit connect speeds
  Mdm   14400  16800  19200  21600  24000  26400  28800  31200  33600 TotCnt
* 0/0       0      0      0      0      0      0      4      4      1      9
* 0/1       2      0      0      0      0      0      3      3      1      9
  0/2       2      0      0      0      0      1      2      4      1     10
* 0/3       0      0      0      1      0      0      3      4      1      9
* 0/4       1      0      0      0      0      2      2      1      1      7
* 0/5       0      0      0      0      0      0      4      4      1      9
* 0/6       0      0      0      0      0      1      3      3      1      8
* 0/7       0      0      0      2      0      0      4      3      1     10
* 0/8       2      0      0      0      0      0      3      4      1     10
* 0/9       0      0      0      0      0      0      4      3      0      7
* 0/10      1      0      0      0      0      1      3      2      1      8
* 0/11      0      0      0      0      0      0      4      3      1      8
  0/12      1      0      0      0      0      0      4      2      1      8
* 0/13      0      0      0      0      0      0      4      2      1      7
* 0/14      1      0      0      0      0      1      2      2      1      7
* 0/15      0      0      0      0      0      0      4      2      1      7
* 0/16      0      0      0      1      0      0      3      2      1      7
* 0/17      1      0      0      0      0      0      4      2      1      8
* 0/18      1      0      0      0      0      0      3      3      1      8
* 0/19      0      0      0      0      0      0      5      3      1      9
* 0/20      0      0      0      0      0      0      4      2      1      7
* 0/21      1      0      0      0      0      0      4      2      0      7
* 0/22      0      0      0      0      0      0      7      9      1     17
* 0/23      0      0      0      0      0      2      2      3      1      8
* 2/0       0      0      0      1      0      0      3      3      1      8
* 2/1       0      0      0      0      0      0      5      2      1      8
* 2/2       0      0      0      1      0      0      4      1      1      7
* 2/3       1      0      0      0      0      0      4      2      1      8
* 2/4       0      0      0      0      0      0      5      2      1      8
* 2/5       0      0      0      0      0      0      4      3      1      8
* 2/6       0      0      0      0      0      0      3      2      1      6
* 2/7       1      0      0      0      0      1      3      2      0      7
* 2/8       1      0      0      0      0      0      3      2      1      7
* 2/9       0      0      0      0      0      1      3      2      1      7
* 2/10      2      0      0      0      0      2      1      0      1      6
* 2/11      0      0      0      1      0      1      3      5      1     11
* 2/12      0      0      0      0      0      0      5      2      1      8
* 2/13      1      0      0      0      0      0      5      0      1      7
* 2/14      1      0      0      0      0      0      3      3      1      8
* 2/15      1      0      0      0      0      1      2      3      1      8
* 2/16      0      0      0      0      0      0      4      3      1      8
* 2/17      0      0      0      0      0      0      5     11      0     16
* 2/18      0      0      0      1      0      1      1      2      1      6
* 2/19      0      0      0      0      0      0      2      3      1      6
* 2/20      1      0      0      0      0      2      3      9      1     16
* 2/21      1      0      0      0      0      0      4      1      1      7
* 2/22      0      0      0      1      0      0      2      3      1      7
* 2/23      0      0      0      0      0      1      3      3      1      8
 Tot       23      0      0      9      0     18    165    141     44    400
 Tot %      5      0      0      2      0      4     41     35     11
  receive connect speeds
  Mdm   14400  16800  19200  21600  24000  26400  28800  31200  33600 TotCnt
* 0/0       0      0      0      0      0      4      1      3      1      9
* 0/1       2      0      0      0      0      3      1      2      1      9
  0/2       2      0      0      0      0      3      1      3      1     10
* 0/3       0      0      0      1      0      3      4      0      1      9
* 0/4       1      0      0      0      0      4      0      1      1      7
* 0/5       0      0      0      0      0      4      3      1      1      9
* 0/6       0      0      0      0      0      4      0      3      1      8
* 0/7       0      0      0      2      0      4      1      2      1     10
* 0/8       2      0      0      0      0      3      0      5      0     10
* 0/9       0      0      0      0      0      4      2      0      1      7
* 0/10      1      0      0      0      0      4      0      2      1      8
* 0/11      0      0      0      0      0      4      0      3      1      8
  0/12      1      0      0      0      0      2      2      2      1      8
* 0/13      0      0      0      0      0      4      1      1      1      7
* 0/14      1      0      0      0      0      2      3      0      1      7
* 0/15      0      0      0      0      0      4      1      1      1      7
* 0/16      0      0      0      1      0      3      2      0      1      7
* 0/17      1      0      0      0      0      4      1      1      1      8
* 0/18      1      0      0      0      0      3      2      1      1      8
* 0/19      0      0      0      0      0      5      1      2      1      9
* 0/20      0      0      0      0      0      4      0      3      0      7
* 0/21      1      0      0      0      0      4      0      1      1      7
* 0/22      0      0      0      0      0      6      6      4      1     17
* 0/23      0      0      0      0      0      4      2      1      1      8
* 2/0       0      0      0      1      0      3      1      2      1      8
* 2/1       0      0      0      0      0      3      3      1      1      8
* 2/2       0      0      0      1      0      4      0      1      1      7
* 2/3       1      0      0      0      0      3      2      1      1      8
* 2/4       0      0      0      0      0      4      2      1      1      8
* 2/5       0      0      0      0      0      4      1      2      1      8
* 2/6       0      0      0      0      0      3      0      3      0      6
* 2/7       1      0      0      0      1      2      2      0      1      7
* 2/8       1      0      0      0      0      3      0      2      1      7
* 2/9       0      0      0      0      0      4      1      1      1      7
* 2/10      2      0      0      0      0      3      0      0      1      6
* 2/11      0      0      0      1      0      3      1      5      1     11
* 2/12      0      0      0      0      0      4      3      0      1      8
* 2/13      1      0      0      0      0      2      3      0      1      7
* 2/14      1      0      0      0      0      3      2      1      1      8
* 2/15      1      0      0      0      0      3      0      3      1      8
* 2/16      0      0      0      0      0      4      0      4      0      8
* 2/17      0      0      0      0      0      5      2      8      1     16
* 2/18      0      0      1      0      0      2      1      1      1      6
* 2/19      0      0      0      0      0      2      2      1      1      6
* 2/20      1      0      0      0      0      4      2      8      1     16
* 2/21      1      0      0      0      0      4      0      1      1      7
* 2/22      0      0      1      0      0      2      0      3      1      7
* 2/23      0      0      0      0      0      4      2      1      1      8
 Tot       23      0      2      7      1    167     64     92     44    400
 Tot %      5      0      0      1      0     41     16     23     11

The following example shows the connection statistics for modem 1/2, which is a V.34 Microcom modem. See the chapter "Modem Management Commands" in the Dial Solutions Command Reference for a complete description of each of the displayed fields:

router# show modem 1/2
Mdm  Typ    Status     Tx/Rx      G  Duration  TX  RX  RTS  CTS  DSR  DCD  DTR
1/2  V34    Idle    26400/28800   1  00:18:42           x    x    x         x
Modem 1/2, Microcom (Select), Async3, TTY3
Firmware (Boot) Rev: 3.1(30) (3.0(4))
DSP Controller (SPX) Rev: 1.1(0) (1.1(0))
Modem config: Incoming and Outgoing
Protocol: reliable/LAPM, Compression: V42bis
Management port config: Status polling and AT session
Management port status: Status polling and AT session
TX signals: -13 dBm, RX signals: -19 dBm
  Last clearing of "show modem" counters never
    122 incoming completes, 6 incoming failures
    0 outgoing completes, 0 outgoing failures
    0 failed dial attempts, 0 ring no answers, 0 busied outs
    0 no dial tones, 0 dial timeouts, 0 watchdog timeouts
    6 no carriers, 0 link failures, 2 resets, 0 recover oob
    0 protocol timeouts, 0 protocol errors, 0 lost events
Transmit Speed Counters:
Connection Speeds         75      300      600     1200     2400     4800
# of connections           0        0        0        0        0        0
Connection Speeds       7200     9600    12000    14400    16800    19200
# of connections           0        0        1        1        2        3
Connection Speeds      21600    24000    26400    28800    31200    32000
# of connections          18       13       51       32        1        0
Connection Speeds      33600    34000    36000    38000    40000    42000
# of connections           0        0        0        0        0        0
Connection Speeds      44000    46000    48000    50000    52000    54000
# of connections           0        0        0        0        0        0
Connection Speeds      56000
# of connections           0
Receive Speed Counters:
Connection Speeds         75      300      600     1200     2400     4800
# of connections           0        0        0        0        0        0
Connection Speeds       7200     9600    12000    14400    16800    19200
# of connections           0        0        1        1        0        3
Connection Speeds      21600    24000    26400    28800    31200    32000
# of connections           2       16       60       39        0        0
Connection Speeds      33600    34000    36000    38000    40000    42000
# of connections           0        0        0        0        0        0
Connection Speeds      44000    46000    48000    50000    52000    54000
# of connections           0        0        0        0        0        0
Connection Speeds      56000
# of connections           0

The next example shows example output for the show modem command. See the chapter "Modem Management Commands" in the Dial Solutions Command Reference for a complete description of each of the displayed fields:

router# show modem
                Inc calls     Out calls     Busied   Failed  No       Succ
  Mdm  Usage    Succ   Fail   Succ   Fail   Out      Dial    Answer   Pct.
* 1/0    37%      98      4      0      0       0        0       0     96%
  1/1    38%      98      2      0      0       0        0       0     98%
  1/2    35%     122      6      0      0       0        0       0     95%
  1/3    37%     104      4      0      0       0        0       0     96%
* 1/4    39%     104      5      0      0       0        1       1     95%
* 1/5    37%      96      4      0      0       0        0       0     96%
* 1/6    37%     120      6      0      0       0        0       0     95%
  1/7    34%     130      5      0      0       0        0       0     96%
  1/8    39%     111      6      0      0       0        1       1     94%
  1/9    37%     108      4      0      0       0        0       0     96%
* 1/10   39%     115      8      0      0       0        0       0     93%
* 1/11   37%      86      3      0      0       0        0       0     96%
* 1/12   38%     121      3      0      0       0        1       1     97%
  1/13   35%     107      6      0      0       0        0       0     94%
* 1/14   37%      92      5      0      0       0        0       0     94%
  1/15   41%     106      9      0      0       0        0       0     92%
  1/16   35%     112      6      0      0       0        0       0     94%
  1/17   39%     101      3      0      0       0        0       0     97%
  1/18   40%     102      7      0      0       0        0       0     93%
  1/19   37%      93      3      0      0       0        0       0     96%
  1/20   42%      97      4      0      0       0        0       0     96%
  1/21   38%      86      5      0      0       0        0       0     94%
* 1/22   40%     104     10      0      0       0        0       0     91%
  1/23   41%      76      5      0      0       0        0       0     93%

Collect Modem Statistics

There are many commands that enable you to display or poll various modem statistics.To show modem performance statistics, perform the following tasks in EXEC mode:
Step Command Purpose

1 . 

show modem [slot/port | group number]

Show various performance statistics for a modem or group of modems.

2 . 

show modem csm [slot/port | group number]

Show the call-switching module status for a modem or group of modems.

3 . 

show modem log [slot/port | group number]1

Show the event log status for a modem or group of modems.

4 . 

show modem summary1

Display the cumulative system statistics for all modems installed in the access server.

5 . 

show modem at-mode1

Display all the active direct connect AT sessions for Microcom modems.

1This command does not apply to basic modems.

Manageable Microcom modems have an out-of-band feature, which is used for polling modem statistics. To configure the system to poll for modem statistics, perform the tasks in the following task table. Unless otherwise specified, all tasks are performed in global configuration mode.
Step Command Purpose

1 . 

modem poll time seconds

Specify the number of seconds between statistical modem polling for Microcom modems. The default is 12 seconds.The configuration range is 2 to 120 seconds.

2 . 

modem poll retry number

Set maximum number of polling attempts to Microcom modems. The default is three polling attempts. The configuration range is from 0 to 10 attempts.1

3 . 

modem status-poll

In line configuration mode, poll for a Microcom modem's status and statistics.

4 . 

modem buffer-size number

Define the number of modem events that each modem is able to store. The default is 100 events for each modem. Use the show modem log command to view modem events.

1If the number of attempts to retrieve modem status or statistics exceeds the number you define, the out-of-band feature is removed from operation. In this case, you must reset the modem hardware using the clear modem command.

Show Modem Example

The following example shows example output for the show modem command:

router# show modem
                Inc calls     Out calls     Busied   Failed  No       Succ
  Mdm  Usage    Succ   Fail   Succ   Fail   Out      Dial    Answer   Pct.
* 1/0    17%      74      3      0      0       0        0       0     96%
* 1/1    15%      80      4      0      0       0        1       1     95%
* 1/2    15%      82      0      0      0       0        0       0    100%
  1/3    21%      62      1      0      0       0        0       0     98%
  1/4    21%      49      5      0      0       0        0       0     90%
* 1/5    18%      65      3      0      0       0        0       0     95%
* 1/6    19%      58      2      0      0       0        0       0     96%
* 1/7    17%      67      5      0      0       0        1       1     93%
* 1/8    20%      68      3      0      0       0        0       0     95%
  1/9    16%      67      2      0      0       0        0       0     97%
  1/10   18%      56      2      0      0       0        1       1     96%
* 1/11   15%      76      3      0      0       0        0       0     96%
* 1/12   16%      62      1      0      0       0        0       0     98%
  1/13   17%      51      4      0      0       0        0       0     92%
  1/14   16%      51      5      0      0       0        0       0     91%
  1/15   17%      65      0      0      0       0        0       0    100%
  1/16   15%      73      3      0      0       0        0       0     96%
  1/17   17%      67      2      0      0       0        0       0     97%
  1/18   17%      61      2      0      0       0        0       0     96%
* 1/19   17%      74      2      0      0       0        0       0     97%
  1/20   16%      65      1      0      0       0        0       0     98%
* 1/21   16%      58      3      0      0       0        0       0     95%
* 1/22   18%      56      4      0      0       0        0       0     93%
* 1/23   20%      60      4      0      0       0        0       0     93%

Show Modem Summary Example

You can display a high level summary of the modems' performance with the show modem summary command:

router# show modem summary
         Incoming calls       Outgoing calls      Busied   Failed   No    Succ
Usage  Succ   Fail  Avail   Succ   Fail  Avail    Out      Dial     Ans   Pct.
  14%  2489    123     15      0      0     15        0        3     3     95%

Show Modem Log Example

The following example shows the event log status for a manageable modem. It also identifies the time elapsed since each modem event was performed (for example, 01:02:41 means the modem event occurred 1 hour, 2 minutes, and 41 seconds ago):

router# show modem log 0/0
Modem 0/0 Events Log:
  01:03:03: Startup Response: Microcom MNP10 K56 Modem (Select)
            Modem (boot) firmware = 3.1(16) (3.0(4))
            DSP Controller (SPX) rev = 204.173(0) (143.191(0))
  01:03:03: Control Reply: 0xFF1F
  01:03:03: RS232 event: RTS  noDTR* CTS* DSR* noDCD* noRI  noTST
  01:03:03: RS232 event: RTS  noDTR  CTS  DSR  noDCD  noRI  noTST
  01:03:03: Modem State event: Idle
  01:03:03: End connection event: Retransmits for MNP block (TX/RX) = 0/0
            Duration = 0:00:00, Number of TX/RX char = 0/0
            Local Disc Reason = Lost Carrier
            Remote Disc Reason = Unknown
  01:03:04: Phone number event:
  01:02:51: DTR event: DTR On
  01:02:51: RS232 event: RTS  DTR* CTS  DSR  noDCD  noRI  noTST
  00:39:52: Startup Response: Microcom MNP10 K56 Modem (Select)
            Modem (boot) firmware = 3.1(16) (3.0(4))
            DSP Controller (SPX) rev = 1.1(0) (1.1(0))

Show Modem AT-Mode Example

The following example shows that modem 1/1 has one open AT directly connected session:

router# show modem at-mode
Active AT-MODE management sessions:
Modem    User's Terminal
1/1 	0 cty 0

Time Interval Example

The following example sets the time interval between polls to 10 seconds using the modem poll time configuration command:

router# configure terminal
router(config)# modem poll time 10

Modem Polling Example

The following example enables modem status polling through the out-of-band feature, which is associated to line  1:

router# configure terminal
router(config)# line 1
router(config-line)# modem status-poll

Polling Attempts Example

The following example configures the server to attempt to retrieve statistics from a local modem up to five times before discontinuing the polling effort:

router# configure terminal
router(config)# modem poll retry 5

Automatically Run a Modem Diagnostics Test

You can automatically run a diagnostics test for on modems inside access servers, such as a Cisco  AS5300 loaded with Microcom modems. Modems that fail the test are automatically busied out of service. To do this, issue the modem autotest global configuration command, which is described in the following sections:


Note The modem autotest feature is not supported on the Cisco 3600 series routers populated with MICA digital modem cards. However, the Cisco 3600 series does support a limited power on startup test, which automatically removes inoperable modems from dial-up services.

How It Works

The access server or router performs the test by automatically conducting a series of back-to-back connections and data transfers between two internal modems. The data transfer consists of sending one packet that is 10-bytes large between two modems. All modem test connections occur inside the system. A modem involved in a back-to-back modem test is temporarily marked as busy, which means the modem will not accept a call while the test is running.

If all modems are currently active and the modem autotest is activated, the test will wait until at least two modems drop their calls and become available. The modem auto test moves on to test a second pair of modems as soon as two additional modems become available, and so on. To disable the modem autotest at any time, issue the no  modem autotest command.

Preliminary Usage Guidelines

We recommend that you set the modem autotest to run during off-peak hours. This provides maximum access to your remote users. For example, if you are an Internet service provider and your peak dial-in hours are between 5:00 p.m. and 12:00 p.m. on weekdays, configure the test to run automatically at 3:00 a.m. on Saturday mornings. Bad or inoperable modems detected by the test will automatically be busied out. See Figure 37.


Figure 37: Sample Demand Curve for Dial Access


There are specific syntax functions used for the modem autotest time hh:mm [interval#] command. The required time hh:mm parameter specifies the start time to initiate the test in hours and minutes (hh:mm; for example 1:00 a.m. is specified as 01:00). By default, the test runs once every 24 hours when enabled. The modem autotest feature synchronizes its timing with the access server's internal clock. The interval# parameter gives you the opportunity to specify which day and hour of the week you want the test to run. In place of the interval parameter specify the hour that you want to start the test, which can be between 1 and 168 hours ahead of the current time. For example, suppose that today is Friday and the current time on the access server is 3:00 p.m. If you want the test to run once every Saturday at 3:00 a.m., enter the modem autotest time 03:00 168 command (03:00 = 3:00 a.m. in military time; 168 = 7 days).

Use the show clock EXEC command to determine the current time set on the access server.

Use the show modem test EXEC command to see the results of the modem autotest. This command displays which modems were tested and the results of the test. You can also use the show modem EXEC command to see which modems are marked bad by the modem autotest command. To disable the test at any time, issue the no modem autotest command.

Set Up the Modem Autotest

To set up the modem autotest, perform the following tasks beginning in EXEC mode:
Step Command Purpose

1 . 

show clock

Take note of the current time set on the access server or router. The modem autotest synchronizes with this time. Be sure this clock matches the current actual time in your time zone.

2 . 

configure terminal

Enter global configuration mode.

3 . 

modem autotest time hh:mm [interval]

Specify the time you want the modem test to automatically begin. Express it in hours and minutes in military time.1

4 . 

modem autotest minimum number

Set the minimum number of modems that will remain untested and available to accept calls during each test cycle. The default is six modems.

5 . 

modem autotest error threshold

Specify a maximum consecutive modem error count that will trigger the modem autotest. You can configure the system to watch for between 3 and 50  errors before the modem autotest begins. To view the list of monitored errors, issue the show modem call-stats command.

6 . 

exit

Return to EXEC mode.

7 . 

show modem test

Display the results of the modem autotest after it has run.

8 . 

show modem

Display the complete list of which modems are marked bad versus good.2

9 . 

clear modem test

Clear the log or test report that is displayed by the show modem test command. If you do not clear the test regularly, eventually the oldest test report will replace by the current test report.

1Do not forget to include the required colon (:) between the hours parameter (hh) and the minutes parameter (mm).
2Inoperable or bad modems are marked with a "B" appearing before the slot/port.

Modem Autotest Example

The following example shows how to set the modem autotest to run once per week on Tuesdays at 3:00 a.m. Additionally, the autotest will activate if the system detects a modem error count higher than 40 errors.

Step 1 Use the set clock EXEC command to determine the current time set on the router or access server. In this example, the time and date set on the following router is 3:00 p.m, Monday, August 25, 1997.

Step 2 Enter global configuration mode and set the modem autotest using the modem autotest time command. In this example, the access server is configured to run the modem autotest every Tuesday at 3:00 a.m.

Step 3 Configure the autotest to activate if the system detects a high modem error count. In this example, the autotest activates if the system detects a modem error count higher than 40  errors. To view the list of monitored errors, issue the show modem call-stats EXEC command.

Step 4 Display the results of the modem autotest after the test has run through a test cycle by issuing the show modem test EXEC command:

Alternatively, you can view which modems were marked bad by the modem autotest by issuing the show modem EXEC command. Bad modems are marked by the letter B. In this example, modem 1/0 and 1/3 are marked bad, which takes them out of commission and makes them unable to participate in dial services.

Manually Isolating a Back-to-Back Modem Test Example

You can also manually isolate an internal back-to-back connection and data transfer between two modems for focused troubleshooting purposes. For example, if mobile users cannot dial in to modem  2/5 (which is the sixth modem port on the modem board in the second chassis slot), attempt a back-to-back test with modem 2/5 and a modem known to be functioning, such as modem 2/6. To do this, issue the test modem back-to-back slot/port slot/port.

You might need to enable this command on several different combinations of modems to determine which one is not functioning properly. A pair of operable modems successfully connect and complete transmitting data in both directions. An operable modem and an inoperable modem do not successfully connect with each other.

Step 1 Perform a back-to-back modem test between two normal functioning modems. This example shows a successful connection between modem 1/1 and modem 1/0, which verifies normal operating conditions between these two modems.

After you enter the test modem back-to-back command, you must define the number of packets transmitted between modems at the Repetitions prompt. The ideal range of packets to transmit and receive is from 1 to 100. The default is 1 packet that is 10-bytes large. The response message (for example, "success/packets = 2/2") tells you how many packets were successfully sent in both directions compared to the total number of packets attempted to be sent in both directions. Because the software reports the packet total in both directions, the reported numbers are two times the number you originally specify.

Step 2 However, when modem 1/1 is tested against modem 1/3, the back-to-back modem test fails. Therefore, modem 1/3 is suspected or proven to be inoperable or bad.

Step 3 Next, you need to manually mark modem 1/3 as an inoperable or bad modem. To do this, you must first find out which line number corresponds with modem 1/3. By issuing the show modem 1/3 EXEC command, you can see that TTY line number 4 (shown as TTY4) is used for modem 1/3.

Step 4 Enter line configuration mode and manually remove modem 1/3 from dial services by issuing the modem bad command on line 4:

Step 5 You can now issue the show modem EXEC command or the show modem slot/port command to display the bad modem status.

Bad modems are marked with the letter B in the show modem command display output:

"Bad" modems are also marked as Bad in the Status column of the show modem slot/port command's display output:

Display Local Disconnect Reasons

Use the show modem call-stats [slot] EXEC command to find out why a modem ended its connection or why a modem is not operating at peek performance.

Local disconnect reasons are listed across the top of the screen display (for example, wdogTimr, compress, retrain, inacTout, linkFail, moduFail, mnpProto, and lapmProt). In the body of the screen display, the number of times each modem disconnected is displayed (see the # column). For a particular disconnect reason, the % column indicates the percent that a modem was logged for the specified disconnect reason with respect to the entire modem pool for that given reason. For example, out of all the times the rmtLink error occurred on all the modems in the system, the rmtLink error occurred 10% of the time on modem 0/22.

Bad or malfunctioning modems are detected by an unusually high number of disconnect counters for a particular disconnect reason. For example, if modem 1/0 had an astronomically high number of compression errors compared to the remaining modems in system, modem 1/0 would probably be bad or inoperable.

To reset the counters displayed by the show modem call-stats command, issue the clear modem counters command.


Note For a complete description of each of the error display fields, see the chapter "Modem Management Commands" in the Dial Solutions Command Reference. Remote disconnect reasons are not described by this command.

The following example displays output for the show modem call-stats command. Due to the screen size limitation of most terminal screen displays, not all the possible disconnect reasons are displayed at one time. Only the top eight most frequently experienced disconnect reasons are displayed at one time.

router# show modem call-stats
  dial-in/dial-out call statistics
       lostCarr  dtrDrop  rmtLink wdogTimr compress  retrain inacTout linkFail
  Mdm     #   %    #   %    #   %    #   %    #   %    #   %    #   %    #   %
* 0/0     6   2    2   3    1   0    0   0    0   0    0   0    0   0    0   0
* 0/1     5   2    2   3    2   1    0   0    0   0    0   0    0   0    0   0
  0/2     5   2    2   3    4   3    0   0    0   0    0   0    0   0    0   0
* 0/3     5   2    2   3    2   1    0   0    0   0    0   0    0   0    0   0
* 0/4     5   2    1   1    1   0    0   0    0   0    0   0    0   0    0   0
* 0/5     5   2    2   3    2   1    0   0    0   0    0   0    0   0    0   0
* 0/6     4   1    2   3    2   1    0   0    0   0    0   0    0   0    0   0
* 0/7     4   1    2   3    4   3    0   0    0   0    0   0    0   0    0   0
* 0/8     6   2    1   1    3   2    0   0    0   0    0   0    0   0    0   0
* 0/9     5   2    1   1    1   0    0   0    0   0    0   0    0   0    0   0
* 0/10    5   2    1   1    2   1    0   0    0   0    0   0    0   0    0   0
* 0/11    5   2    1   1    2   1    0   0    0   0    0   0    0   0    0   0
  0/12    5   2    2   3    2   1    0   0    0   0    0   0    0   0    0   0
* 0/13    5   2    1   1    1   0    0   0    0   0    0   0    0   0    0   0
* 0/14    5   2    1   1    1   0    0   0    0   0    0   0    0   0    0   0
* 0/15    5   2    1   1    1   0    0   0    0   0    0   0    0   0    0   0
* 0/16    5   2    1   1    1   0    0   0    0   0    0   0    0   0    0   0
* 0/17    5   2    1   1    2   1    0   0    0   0    0   0    0   0    0   0
* 0/18    5   2    1   1    2   1    0   0    0   0    0   0    0   0    0   0
* 0/19    5   2    1   1    3   2    0   0    0   0    0   0    0   0    0   0
* 0/20    5   2    1   1    1   0    0   0    0   0    0   0    0   0    0   0
* 0/21    5   2    1   1    1   0    0   0    0   0    0   0    0   0    0   0
* 0/22    5   2    1   1   11  10    0   0    0   0    0   0    0   0    0   0
* 0/23    5   2    1   1    2   1    0   0    0   0    0   0    0   0    0   0
* 2/0     4   1    2   3    2   1    0   0    0   0    0   0    0   0    0   0
* 2/1     5   2    1   1    2   1    0   0    0   0    0   0    0   0    0   0
* 2/2     5   2    2   3    0   0    0   0    0   0    0   0    0   0    0   0
* 2/3     5   2    1   1    2   1    0   0    0   0    0   0    0   0    0   0
* 2/4     5   2    1   1    2   1    0   0    0   0    0   0    0   0    0   0
* 2/5     5   2    1   1    2   1    0   0    0   0    0   0    0   0    0   0
* 2/6     4   1    1   1    1   0    0   0    0   0    0   0    0   0    0   0
* 2/7     5   2    1   1    1   0    0   0    0   0    0   0    0   0    0   0
* 2/8     5   2    1   1    1   0    0   0    0   0    0   0    0   0    0   0
* 2/9     4   1    1   1    2   1    0   0    0   0    0   0    0   0    0   0
* 2/10    5   2    1   1    0   0    0   0    0   0    0   0    0   0    0   0
* 2/11    5   2    1   1    5   4    0   0    0   0    0   0    0   0    0   0
* 2/12    5   2    1   1    2   1    0   0    0   0    0   0    0   0    0   0
* 2/13    5   2    1   1    1   0    0   0    0   0    0   0    0   0    0   0
* 2/14    5   2    1   1    2   1    0   0    0   0    0   0    0   0    0   0
* 2/15    4   1    1   1    3   2    0   0    0   0    0   0    0   0    0   0
* 2/16    4   1    1   1    3   2    0   0    0   0    0   0    0   0    0   0
* 2/17    5   2    2   3    9   8    0   0    0   0    0   0    0   0    0   0
* 2/18    4   1    1   1    1   0    0   0    0   0    0   0    0   0    0   0
* 2/19    3   1    1   1    2   1    0   0    0   0    0   0    0   0    0   0
* 2/20    7   3    1   1    8   7    0   0    0   0    0   0    0   0    0   0
* 2/21    5   2    1   1    1   0    0   0    0   0    0   0    0   0    0   0
* 2/22    4   1    1   1    2   1    0   0    0   0    0   0    0   0    0   0
* 2/23    5   2    1   1    2   1    0   0    0   0    0   0    0   0    0   0
 Total  233       59      110        0        0        0        0        0
  dial-out call statistics
         noCarr noDitone     busy    abort dialStrg autoLgon dialTout  rmtHgup
  Mdm     #   %    #   %    #   %    #   %    #   %    #   %    #   %    #   %
* 0/0     1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/1     0   0    0   0    0   0    0   0    0   0    0   0    0   0    0   0
  0/2     0   0    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/3     1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/4     1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/5     0   0    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/6     1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/7     5   5    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/8     0   0    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/9     1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/10    0   0    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/11    5   5    0   0    0   0    0   0    0   0    0   0    0   0    0   0
  0/12    0   0    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/13    0   0    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/14    1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/15    1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/16    2   2    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/17    4   4    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/18    5   5    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/19    1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/20    0   0    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/21    0   0    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/22    5   5    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 0/23    1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/0     2   2    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/1     3   3    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/2     0   0    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/3     0   0    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/4     0   0    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/5     1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/6     1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/7     4   4    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/8     7   8    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/9     4   1    1   1    2   1    0   0    0   0    0   0    0   0    0   0
* 2/10    1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/11    1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/12    1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/13    1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/14    4   4    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/15    1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/16    1   1    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/17    5   5    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/18    5   5    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/19    3   3    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/20    0   0    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/21    4   4    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/22    2   2    0   0    0   0    0   0    0   0    0   0    0   0    0   0
* 2/23    0   0    0   0    0   0    0   0    0   0    0   0    0   0    0   0
 Total   84        0        0        0        0        0        0        0

Remove Inoperable Modems

This section describes how to manually remove inoperable or bad modems from dial-up services.

You can perform the following optional tasks in line configuration mode:
Step Command Purpose

1 . 

modem bad

Remove and idle modem from service and indicate it as suspected or proven to be inoperable.

2 . 

modem hold-reset

Reset and isolate the modem hardware for extensive troubleshooting.

3 . 

modem busyout

Gracefully disable a modem from dial services.

4 . 

modem shutdown

Abruptly shut down a modem from dial service.

5 . 

modem recovery-time minutes

Set the maximum amount of time the call-switching module waits for a local modem to respond to a request before it is considered locked in a suspended state. The default is five minutes.

If you use the modem bad command to remove an idle modem from dial services and mark it as inoperable, the letter B is used to identify the modem as bad. You can see the letter B for modems that are marked bad by looking at the Status column in the show modem slot/port command's output. Additionally, look at the far left column in the show modem command's output. Use the no modem bad command to unmark a modem as B and restore it for dial-up connection services. If the letter b appears next to a modem number, it means the modem was removed from service with the modem shutdown command or the modem busyout command.


Note Only idle modems can be marked bad by the modem bad command. If you want to mark a modem bad that is actively supporting a call, first issued the modem shutdown command then issue the modem bad command.

Use the modem hold-reset command if you are experiencing extreme modem behavior (for example, if the modem is uncontrollably dialing in to the network). This command prevents the modem from establishing software relationships such as those created by the test back-to-back modem command and the modem autotest command. The modem is unusable while the modem hold-reset command is configured. The modem hold-reset command also resets a modem that is frozen in a suspended state. Disable the suspended modem with the modem hold-reset command, and then restart hardware initialization with the no modem hold-reset command.

The following example disables a suspended modem and resets its hardware initialization:

router# configure terminal
router(config)# line 4
router(config-line)# modem hold-reset
router(config-line)# no modem hold-reset

The following example gracefully disables the modem associated with line 1 from dialing and answering calls. The modem is disabled only after all active calls on the modem are dropped.

router# configure terminal
router(config)# line 1
router(config)# modem busyout

The following example abruptly shuts down the modem associated with line 2. All active calls on the modem are dropped immediately.

router# configure terminal
router(config)# line 2
router(config)# modem shutdown

In the following example, the modem using TTY line 3 is actively supporting a call. However, we want to mark the modem bad because it has poor connection performance. First abruptly shut down the modem and drop the call with the modem shutdown command then issue the modem bad command to take the modem out of service.

router# show modem
                Inc calls     Out calls     Busied   Failed  No       Succ
  Mdm  Usage    Succ   Fail   Succ   Fail   Out      Dial    Answer   Pct.
1/0    37%      98      4      0      0       0        0       0     96%
  1/1    38%      98      2      0      0       0        0       0     98%
* 1/2    2%              3              99         0      0       0        0       0     1%
...
router# configure terminal
router(config)# line 3
router(config)# modem shutdown
router(config)# modem bad
router(config)# exit
router# show modem
                Inc calls     Out calls     Busied   Failed  No       Succ
  Mdm  Usage    Succ   Fail   Succ   Fail   Out      Dial    Answer   Pct.
1/0    37%      98      4      0      0       0        0       0     96%
  1/1    38%      98      2      0      0       0        0       0     98%
B 1/2    2%              3              99         0      0       0        0       0     1%


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