Cisco 1603R User Manual page 57

Figure A-1 Troubleshooting ISDN (Continued)
Symptom
NT1 LED is on.
OK LED (next to ISDN S/T port) is off
(Cisco 1604).
Cisco 1604 cannot create an ISDN connection to
the remote router when an ISDN device is
connected to the ISDN S/T port.
ISDN device attached to the Cisco 1604 ISDN S/T
port does not operate correctly.
Checks
• If there is no device
connected to the ISDN S/T
port, the OK LED should be
off.
• Is the device connected to
the ISDN S/T port turned on
and correctly configured?
• Is the ISDN configured for
multipoint service?
• Is the external ISDN device
using both B channels?
• Does the device operate
correctly if the interface for
the Cisco 1604 ISDN U port
(interface bri0) is shut
down?
• Is the Cisco 1604 using both
B channels?
Troubleshooting ISDN
Causes and Solutions
• Possible router hardware
problem.
• Possible problem with
device connected to the
ISDN S/T port.
• The service provider should
configure the line for
multipoint service.
• The service provider should
configure the line for
multipoint service.
• The service provider should
configure the line for
multipoint service.
• The service provider should
configure the line for
multipoint service.
Troubleshooting A-9