Information Technology Reference
In-Depth Information
For dialer profiles, a map class must be defined to set the speed. Note that, by default, ISDN interfaces
attempt to use 64K communications speeds on each channel.
For detailed information on configuring dialer maps and profiles, refer to the
Cisco IOS Dial Solutions
Configuration Guide
,
Dial Solutions Command Reference
, and
Dial Solutions Quick Configuration
Guide.
Getting valid PPP packets indicates that the link is up and working. Proceed to the section
“Troubleshooting PPP
.
”
Incoming CAS Call Troubleshooting
To troubleshoot the CAS group serving connectivity to the modems, use the commands
debug modem
,
debug modem csm
, and
debug cas
.
The
debug cas
command first appeared in 12.0(7)T for the AS5200 and AS5300. Earlier
versions of IOS use a system-level configuration command
service internal
, along with the
exec command
modem-mgmt debug rbs
. Debugging this information on an AS5800
requires connecting to the trunk card itself.
Note
The first thing to look for is if the telco switch went off-hook to signal the incoming call. If not, verify
the number being called by attaching a phone to the originating side's phone line and then calling the
number. If the call comes in, the problem is in the originating CPE. If the call still does not show up on
the CAS, check the T1 (per Chapter 15, “Troubleshooting Serial Lines”). A good debug to use in this
instance is
debug serial interfaces.
The following shows a good connection using
debug modem CSM
:
Router#
debug modem csm
CSM_MODEM_ALLOCATE: slot 1 and port 0 is allocated.
MODEM_REPORT(0001): DEV_INCALL at slot 1 and port 0
CSM_PROC_IDLE: CSM_EVENT_ISDN_CALL at slot 1, port 0
CSM_RING_INDICATION_PROC: RI is on
CSM_RING_INDICATION_PROC: RI is off
CSM_PROC_IC1_RING: CSM_EVENT_MODEM_OFFHOOK at slot 1, port 0
MODEM_REPORT(0001): DEV_CONNECTED at slot 1 and port 0
CSM_PROC_IC2_WAIT_FOR_CARRIER: CSM_EVENT_ISDN_CONNECTED at slot 1, port 0
If this code is seen, then the call was directed to a modem. Proceed to the “Incoming Modem Call
Troubleshooting” section.
Incoming Modem Call Troubleshooting
The debugs used in troubleshooting incoming modem calls are listed here:
debug modem
debug modem csm
(for integrated digital modems)
These other debugs are used in conjunction to indicate the new call coming in:
debug isdn q931
debug cas
Assuming that the call reaches the modem, the modem must pick up the call.
