How bind media|control source-interface command modify the SDP ?

[david.alfaro1]

Hello Dears,

I know that the bind media|control source-interface command influences in the source of a SIP request whether the network is routing the same interface or another one. So, signaling/control and media binding are used to change the source IP address information in layer 3 packets and of course Layer 7 SIP headers specially in the SIP SDP message body.

In order of the above, when this command handles a SIP request SDP header, I am wondering to know, to handle the source IP address, specifically what SIP request SDP field is handled, is the o= field or the c= field, or both?

The documentation just say that the command handle the source IP address in the SIP request, but it does not specify which SIP request SDP field o fields (c= or o= or both) the bind command handle the source IP address in, or if the one of these fields (maybe the o=) remains equal as the routing cef table or it is modified too by the bind command, or both of them (o= or/and c=).

Kind regards,

[Roger Kallberg]

Purely speculative but instinctively I would say that it affects all of these fields in the SDP. However to be absolutely sure I would recommend you to do your own verification on this by setting different interfaces for the bind statements and capture the output from debug ccsip message for each test call.