Troubleshooting Isdn - Cisco 1720 Hardware Installation Manual

Table 3-3 Troubleshooting the Power System
Symptom
The front-panel PWR LED is on, the
front-panel OK LED is off, and the router
does not pass console or EIA data.

Troubleshooting ISDN

Cisco 1700 Router Hardware Installation Guide
3-10
Possible Cause(s)
The power supply has failed.
Because ISDN uses many variables and supports many different configurations, it
sometimes can cause problems for the router. This section describes problems
related to the ISDN line that might occur.
Two commands are useful when troubleshooting ISDN:
For routers with an ISDN S/T WAN interface card, enter the clear interface
•
command to terminate any active ISDN calls and to reset the ISDN BRI
interface. Do this for each ISDN port installed in the router:
Router# clear interface bri0
Router# clear interface bri1
For routers with an ISDN U WAN interface card(s), use the clear controller
•
command to terminate any active ISDN calls, to reset the ISDN BRI
interface, and to reset the ISDN line between the router and the central office
switch. Do this for each ISDN port installed in the router:
Router# clear controller bri0
Router# clear controller bri1
Table 3-4 lists troubleshooting methods for ISDN-specific problems that might
occur.
Chapter 3 Troubleshooting
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