Information Technology Reference
In-Depth Information
Verify that isdn switchtype and pri-group Are Configured Correctly
Use the
show running-config
command to check if isdn switchtype and pri-group timeslots are
configured correctly. Contact your service provider for correct values.
To change the isdn switchtype and pri-group, enter these lines:
maui-nas-03#
configure terminal
maui-nas-03(config)#
isdn switch-type primary-5ess
maui-nas-03(config)#
controller t1 0
maui-nas-03(config-controlle)#
pri-group timeslots 1-24
Verifying the Signaling Channel
If the error counters do not increase but the problem persists, verify that the signaling channel is up and
configured correctly.
Step 1
Run the
show interface serial x:23
command, where x should be replaced by the interface number.
Step 2
Check to see if the interface is up. If the interface is not up, use the
no shutdown
command to bring the
interface up.
maui-nas-03#
config terminal
Enter configuration commands, one per line. End with CNTL/Z.
maui-nas-03(config)#
interface serial 0:23
maui-nas-03(config-if)#
no shutdown
Step 3
Ensure that encapsulation is PPP. If the interface is not using PPP, then use the
encapsulation ppp
command in the interface configuration mode to correct it.
maui-nas-03(config-if)#
encapsulation ppp
Step 4
Check to see whether loopback is set. Loopback should be set only for testing purposes. Use the
no
loopback
command to remove loopbacks.
maui-nas-03(config-if)#
no loopback
Step 5
Power-cycle the router.
Step 6
If the problem persists, contact your service provider or Cisco TAC.
Troubleshooting a PRI
Whenever troubleshooting a PRI, you need to check whether the T1 is running cleanly on both ends. If
Layer 1 problems have been resolved, as described previously, we must look to Layer 2 and 3 problems.
Troubleshooting Using the show isdn status Command
The
show isdn status
command is used to display a snapshot of all ISDN interfaces. It displays the status
of Layers 1, 2, and 3.
Verify that Layer 1 is active.
The Layer 1 status should always say ACTIVE unless the T1 is down.
Step 1
