Incoming calls to IP phones through an H.323 gateway fail with a re-order tone

[TCC_2]

Core Issue

You may encounter these symptoms:

• No ringback, silence, or dead air.

• Busy Tone.Refer to A busy tone is received when the user calls across a gateway over a dial peer with a default codec

• Call never completes.Refer toIncoming calls to IP phones are disconnected when coming through an H.323 gateway
  
• Reorder tone. This issue is discussed in the resolution.

Resolution

To address this issue, perform these steps:

1. Verify that the VoIP dial peer configuration on the Cisco IOS  gateway is pointing to the correct IP address of the Cisco CallManager, which is the IP address configured in session target ipv4:x.x.x.x command under the VoIP dial peer. Refer to Configuring a Cisco IOS H.323 Gateway for Use with Cisco CallManager   
   
2. In the gateway configuration screen of the Cisco CallManager, verify that the number of significant digits mentioned corresponds to the number of digits in your dialing plan.    
   
3. If any digits are prepended using the prefix Distinguished Name (DN) option on this screen, ensure the new digit string matches the DN. If it does not match, then remove ormodify the prefixed digits and update. Reset the gateway after making the necessary changes.    
   
4. If you are using translation patterns for digit manipulation, ensure that the called party is reachable by the calling party. To address Calling Search Space Partition issues, refer to Understanding and Using Partitions and Calling Search Spaces With Cisco CallManager, and ensure the transformation masks match valid DN's or route patterns. Refer to Translation Pattern to understand how translation patterns work in Cisco CallManager.    
   
5. If the Called IP phone is in a partition, the most common reason for receiving re-order (fast busy) is that the calling party does not have the rights to call the called party. In the case of calls from the PSTN, the Calling Search Space (CSS) that the gateway belongs to must include the partition of the called party. For more on CCS and partitions, refer to Understanding and Using Partitions and Calling Search Spaces With Cisco CallManager 3.0   
   
6. If any CSS or partitions are used, restart the devices in the CSS from the Route Plan menu. Do the same for partitions, and reset the gateway.    
   
7. If no CSS or partitions are used, restart the gateway and the IP phone.

If none of these procedures help, perform the procedure in Setting up Cisco CallManager Traces for the TAC, and capture the failed call. These traces could be presented to TAC for further analysis