The show isdn status command displays the status of all ISDN interfaces or a specific ISDN interface.
When troubleshooting ISDN Basic Rate Interface (BRI), it is necessary to first determine if the router can properly communicate with the Telco ISDN switch.
Once this has been verified, you can proceed on to higher level troubleshooting issues.
Layer 1 status – physical layer connectivity
Layer 2 status – Terminal Endpoint Identifier (TEI) Number and mulitiframe structure
The valid TEI number range = 64 to 126
Layer 1 status – physical layer connectivity
Layer 2 status – Terminal Endpoint Identifier (TEI) Number and mulitiframe structure
The valid TEI number range = 64 to 126
The most often seen Layer 2 states are;
- MULTIPLE_FRAME_ESTABLISHED
This indicates that the state is under normal operations.
- TEI_ASSIGNED
This indicates that the router has lost connectivity to the switch. It is not the usual case unless the Telco (commonly in EU) deactivates Layer 1 and 2 when there are no active calls.
Troubleshoot commands
Debug isdn q921 or q931(If the Layer 3 issues)
Clear interface bri
Service Profile Identifiers (SPID) status
· state = 1(terminal down)
· state = 3(await establishment)
· state = 5(init)
· state = 6(not initialized)
- MULTIPLE_FRAME_ESTABLISHED
This indicates that the state is under normal operations.
- TEI_ASSIGNED
This indicates that the router has lost connectivity to the switch. It is not the usual case unless the Telco (commonly in EU) deactivates Layer 1 and 2 when there are no active calls.
Troubleshoot commands
Debug isdn q921 or q931(If the Layer 3 issues)
Clear interface bri
Service Profile Identifiers (SPID) status
· state = 1(terminal down)
· state = 3(await establishment)
· state = 5(init)
· state = 6(not initialized)
· state = 8(established)