Slow Forwarding Failure of the Console Because the Peer Office Does Not Support the G711U Encoding

Publication Date:  2015-07-14 Views:  131 Downloads:  0
Issue Description
Network: IMS --> SBC --> SoftCo5816 --> Console server --> SoftConsole

SoftCo5816 IP address: 10.194.72.147
Console server IP address: 10.194.72.146
SoftConsole IP address: 10.194.72.145
SoftCo version: SoftCo V100R002C04SPC700
SoftConsole version: V100R001C02SPC100

An outer-office user (whose phone number is 13588868597) calls the console access code (057455339999), and the agent on the SoftConsole (8989) picks up the phone and clicks Hold. The outer-office user hears the announcement indicating that the call is held. Then, the agent calls the requested internal extension number (2456) and talks with the intra-office user. However, when the agent clicks Forward, all calls are disconnected.
Handling Process
Step 1 Capture and analyze SoftConsole logs.

The SoftCo sends a NOTIFY message with 200 OK to the peer office, indicating a forwarding success.



Step 2 Capture and analyze SoftCo5816 logs.

The terminal under the SoftCo sends an INVITE message to the mobile phone, and the mobile phone returns a 488 error message. The SoftCo negotiates with the mobile phone to use the G711A codec and negotiates with the intra-office phone to use the G711U codec. When the agent talks with the intra-office user and transfers the call, the codec mode used between the SoftCo and the intra-office phone is used for negotiation with the mobile phone. The INVITE message carries the G711U codec that is not supported by the peer office. Therefore, the call cannot be forwarded.



Step 3 Change the voice codec priorities. The codec ranked first has the highest priority.

config system codetype <g711a&g711u&g729&g723&ilbc_1520&ilbc_1333>

----End
Root Cause
Possible Cause:
  1. The SoftConsole is faulty.
  2. The codec configurations on the SoftCo5816 are incorrect.

Diagnosis Flow:
Trace SoftConsole logs and network packets, and use the UCMaint to analyze SoftCo logs.
 

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