System information

Troubleshooting ISDN
Book Title
17-380
ISDN: Dial Does Not Go Through BRI
Symptom: ISDN router using a Basic Rate Interface (BRI) port successfully dials, but the call does
not go through.
Table 17-2 outlines the problems that might cause this symptom and describes solutions to those
problems.
Table 17-2 ISDN: Dial Does Not Go Through BRI
Possible Problem Solution
Speed setting mismatch
Step 1 Use the show running-config privileged exec command to view the
router configuration. Check the dialer map interface configuration
command entries in the local and remote router. These entries should
look similar to the following:
dialer map ip 131.108.2.5 speed 56 name C4000
Step 2
Compare the speed setting configured on the router interface to the
speed of your ISDN service. The speeds must be the same. To set the
speed on the router, use the speed 56 | 64 keyword in the dialer map
command.
Step 3 If you do not know the speed of your ISDN service, contact your
ISDN provider. Long-distance calls are usually 56 kbps.
For detailed information on configuring dialer maps, refer to the Cisco IOS
Wide-Area Networking Configuration Guide and Wide-Area Networking
Command Reference.
Misconfigured dialer map
Step 1 Use the show running-config privileged exec command to view the
router configuration. Look for dialer map interface configuration
command entries.
Step 2 Make sure that each dialer map contains the phone number of the
remote BRI.
Step 3 If the phone number of the remote BRI is properly specified in each
dialer map statement but the dial does not go through, the first call
failed and there are no numbers left to try.
Step 4 Make sure that a phone number is configured, and then clear the
interface using the clear interface privileged exec command and try
dialing again.
For detailed information on configuring dialer maps, refer to the Cisco IOS
Wide-Area Networking Configuration Guide and Wide-Area Networking
Command Reference.