Page History

...

For example, in the default Q.850 to SIP override table, QSIG Cause Codes 34, 38, 41, 42, 47, 58, and 88 map to 503 Service Unavailable. A problem occurs when the Sonus SBC 1000/2000 receives Cause Code 34 from the PSTN. The Sonus SBC 1000/2000 maps it to 503 Service Unavailable, which causes Lync to declare the Sonus SBC 1000/2000 gateway unavailable with Event ID 46046. In this case, the Sonus SBC 1000/2000 administrator may want to override the default mapping in order to prevent Lync from flagging the whole gateway as unavailable. Consider the following illustration.

This article expands more on this practice, and describes how to configure the Sonus SBC 1000/2000 to perform custom SIP response mapping for SIP to SIP calls.

...

In this example we use the SIP to Q850 and Q850 to SIP Override Tables. Upon receiving a SIP response, the Sonus SBC 1000/2000 uses the SIP to Q850 Override Table to map the SIP response to a Q850 Cause Code. Once the Q850 Cause Code is found, the Sonus SBC 1000/2000 uses the Q850 Cause Code, via the Q850 to SIP mapping table, to map it to a SIP response. This behavior is achieved when the default Pass-through SIP Response Code feature is disabled.

Default Q.850 to SIP and SIP to Q.850 Mapping Tables in Sonus SBC 1000/2000

...

• Create a SIP to Q.850 mapping table, which will be used to match the SIP Response to a Q.850 Cause Code for inbound calls.

• Create a Q.850 to SIP mapping table, which will be used to match the Q.850 Cause Code to SIP Response for outbound calls.

• Disable Pass-through Peer SIP Response Code and select the two mapping tables.