What does rport without port number mean in SIP
When you have a SIP Via: header like
example.txt
Via: SIP/2.0/UDP 95.117.121.206:18050;rport;branch=z9hG4bKabc123the rport parameter means respond to the port from which the request was received
This is extremely useful in case of NAT traversal because you don’t know upfront which outgoing NAT port your packets will be mapped to.
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