Cisco 1603R User Manual page 56

Troubleshooting ISDN
Figure A-1 lists troubleshooting methods for ISDN-specific problems that might occur.
Figure A-1 Troubleshooting ISDN
Symptom
Router is on:
OK LED (next to ISDN S/T port) is off
(Cisco 1603 and ISDN S/T WAN interface card).
Router is on:
NT1 LED is off
(Cisco 1604 and ISDN U WAN interface card).
A-8 Cisco 1600 Series Router Hardware Installation Guide
Checks
• Is the SYSTEM OK LED
on?
• Are all ISDN cables
properly connected?
• Is the NT1 LED on?
• Is the SYSTEM OK LED
on?
• Are all ISDN cables
properly connected?
• Is the ISDN line connected
to the router ISDN U port?
Causes and Solutions
• Possible router hardware
problem.
• Possible ISDN line
problem. Check with ISDN
service provider.
• Possible NT1 problem.
• Possible router hardware
problem.
• Possible ISDN line
problem. Check with ISDN
service provider.
• Possible ISDN line
problem. Check with ISDN
service provider.