final response, then it is possible that the SDP answer that was forwarded to the INVITE-
initiating UA is not relevant, and media synchronization is needed between the two UAs.
Media synchronization is done by sending a re-INVITE request immediately after the call is
established. The re-INVITE is sent without an offer to the INVITE-initiating UA. This causes
the UA to send an offer which is forwarded to the UA that confirmed the call. The media
synchronization process is enabled by the EnableSBCMediaSync parameter.
30.11 Alternative Routing on Detection of Failed SIP
Response
The device can detect failure of a sent SIP response (e.g., TCP timeout, and UDP ICMP).
In such a scenario, the device re-sends the response to an alternative destination. This
support is in addition to alternative routing if the device detects failed SIP requests.
For example, assume the device sends a SIP 200 OK in response to a received INVITE
request. If the device does not receive a SIP ACK in response to this, it sends a new 200
OK to the next alternative destination. This new destination can be the next given IP
address resolved from a DNS from the Contact or Record-Route header in the request
related to the response.
To Next Page
Loading...
