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Cisco 1760 Modular Access Router Hardware Installation Guide
78-13342-03
Chapter3 Troubleshooting
Problem-Solving
Fan Behavior
The fans in the Cisco 1760 router are always on. They are not thermostatically
controlled, but they are normally operational.
ISDN S/T
or
ISDN U
Card cannot
make a
connection to
the remote
router.
Use show isdn status
command to check the
following:
Does the current ISDN
switch type match actual
switch type being used?
Use the isdn switch-type command
to configure correct switch type.
Is Layer 1 status
deactivated?
•Verify that all ISDN cabling is
connected properly.
•Use the show controller bri0
command to check for the
message CO RUNNING
LOOPBACK TESTS or CO
TESTING. If you receive either
message, contact your ISP.
If Layer 1 status is active,
does Layer 3 status say “2
Active Layer 3 calls”?
Router might have called itself.
Check destination phone number
configured with the dialer map
command or the dialer string
command.
If Layer 1 status is active,
does Layer 3 status say
“No Active Layer 3
call(s)”?
Make sure that the destination phone
number matches the remote router
phone number. Make sure that the
route to the destination matches the
remote router network address.
If Layer 1 status is active,
does Layer 3 status say “1
Active Layer 3 call”?
Check the router protocol
configurations.
Table3-4 Troubleshooting ISDN (continued)
WIC Symptom Check the Following Possible Solutions