Cisco 1751 - Manual (Page 54)

Chapter 3 Troubleshooting
Problem Solving
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Cisco 1751 Router Hardware Installation Guide
78-11258-04
Troubleshooting ISDN
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 WIC, 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 bri0/0
Router# clear interface bri1/0
• For routers with an ISDN U WIC, 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.
The router is on, but the front-panel
PWR LED is off. The power supply has failed. Return the router to your
Cisco reseller.
The front-panel PWR LED is on, the
front-panel OK LED is off, and the
router does not pass console or EIA
data. The power supply has failed. Return the router to your
Cisco reseller.
Table 3-3 Troubleshooting the Power System
Symptom Possible Solution(s)