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rport and symmetric responses
RFC 3581 adds rport so the response is sent to the source address and port the request came from.
Learn in 5 minutes
- Add rport on Via when you need symmetric response routing
- Read received and rport on the response Via
- Keep rport separate from RTP NAT traversal
Visual
The server answers the source it observed. rport does not rewrite SDP.
Worked example
Read rport on the response Dissect the 100 Trying. Via has received and rport filled in.
- Press Dissect.
- Find rport.
- State which port receives the response.
Fault
The client set rport. The server still sends responses to 203.0.113.10:5060 and they never arrive. The request source port was 49160.
RFC 3581 sends the response to the observed source and records received and rport.
Quiz
Ecosystem
Glossary, sister systems, and the integration seam for this room.
Quality management and recording QM scores interactions. The standardized way an SBC forks a session to a recorder is SIPREC.