Specifications

6-11
Cisco AS5x00 Case Study for Basic IP Modem Services
11/24/1999
Section 6 Modem Management Operations
Configuring Modems Using Modem Autoconfigure
2.1 Basic Rules for Modem Autoconfigure
The following list describes the basic rules:
1.
Never use the
modem autoconfigure discovery
command. Applying specific modemcaps reduces
the risk of error.
2.
Always use the
modem autoconfigure type
modem-name
command. This command improves your
modem’s performance. See CSCdk15302 for an explanation.
The
modem autoconfigure type mica
command can be used to reset any integrated modem (not
only MICA), back to its factory defaults. The keyword
mica
is a built-in modemcap that only
functions as &F (return to defaults).
3.
When you use the
modem autoconfigure
command, be sure that any script reset function is
removed. A script reset is redundant and possibly harmful.
A script reset is a chat script that is applied to a line when the line resets. The modem autoconfigure
function is applied when the system starts up, not just when the line resets.
4.
When creating a modemcap, ignore all the strange and confusing fields. Put your modem init string
into the MSC (Miscellaneous) field:
`
Always start your init string with &F (or, for non-cisco modems, with the preferred &F1, &F2,
etc.)
`
Never put an &W into an init string. An &W can wear out the EPROM on modems where this
is not a no op (that is, a statement or operation that does nothing).
`
For MICA modems, always be sure that &D2 (not &D3) is in effect. See CSCdk15260 and
CSCdk15302 for an explanation.
2.2 Modem Autoconfigure K56Flex Example
The following modem-autoconfigure string disables V.8bis/K56Flex. The string &F&D2s53=0 is
applied to two MICA modems. Disabling V.8bis reduces trainup time by about two seconds, and it
prevents trainup problems with older client modems.
Step 1
Watch the modem autoconfigure function run, so you can see if there are any typos in the modem string:
5300-NAS#debug confmodem
Modem Configuration Database debugging is on
5300-NAS#show debug
Modem Autoconfig:
Modem Configuration Database debugging is on
5300-NAS#terminal monitor
Step 2
Remove any previous modem autoconfigure entry:
5300-NAS#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
5300-NAS(config)#no modemcap entry mica-noKflex
% Modemcap entry 'mica-noKflex' does not exist
Step 3
Add the new entry:
5300-NAS(config)#modemcap edit mica-noKflex misc &F&D2s53=0