- Gold, 750 points or more
Outgoing calls to Public Switched Telephone Network (PSTN) through an H.323 gateway could fail with these symptoms:
- No ringback.
- Silence or dead air.
- Call never completes. If the call never completes through a T1 PRI link, Outgoing calls from IP phones to a PSTN through a T1, E1, or PRI link on a H.323 or MGCP gateway are never completed or give a fast busy tone. If the circuit is an analog E&M or analog Foreign Exchange Office (FXO) or Foreign Exchange Station (FXS) port, verify that those circuits are operational. For more help, refer to these cases:
- Reorder tone. If the reorder tone is heard before the complete number is dialed refer Outgoing calls to PSTN or PBX network through a Cisco IOS gateway fail with a re-order tone before the complete number is dialed . The resolution discusses a case where the the reorder tone is heard after all the digits are dialed.
For outgoing call connection issues through a Media Gateway Control Protocol (MGCP) gateway, refer toOutgoing calls to a PSTN or PBX network through a MGCP gateway fail with symptoms like dead air or re-order tone
If the reorder tone is heard after the complete number is dialed, then digit manipulation can occur at the route pattern, route list or by use of translation patterns.Refer External calls fail through the gateway router on Cisco CallManager - user hears the reorder (or fast busy) tone
To address this issue, perform these steps:
- When using translation patterns for digit manipulation, ensure that the called party is reachable by the calling party. For information on calling search space partition issues, refer to Understanding and Using Partitions and Calling Search Spaces With Cisco CallManager. Ensure the transformation masks match valid Distinguished Names (DNs) or route patterns. Refer to Translation Pattern to understand how translation patterns work in Cisco CallManager.
- Verify that the manipulated digit string or the dialed number (if not manipulated) matches the correct dial-peer on the gateway. Refer to Understanding How Inbound and Outbound Dial Peers are Matched on Cisco IOS Platforms.
- If the dial-peer matches correctly, confirm that the Device Name field in the gateway configuration screen on the Cisco CallManager has the correct IP address for the H.323 gateway. Refer to Configuring a Cisco IOS H.323 Gateway for Use with Cisco CallManager to verify the gateway configuration.
- If none of the above steps help resolve the problem, Outgoing calls from IP phones to a PSTN through a T1, E1, or PRI link on a H.323 or MGCP gateway are never completed or give a fast busy tone as well as these cases if you are using analog circuits to connect to the PBX/PSTN: