Source note · SIP registration failures
A server receiving a Via with an empty rport must fill in the request's source port, and for UDP it must send the response to the IP in the received parameter and the port in rport.
Checked 2026-09-25
- Vendor
- not restricted
- Product
- SIP
- Subsystem
- nat-traversal
- Deployment
- any
- Region
- not restricted
- Release range
- RFC 3581
- Checked
- 2026-09-25
Sources
- RFC 3581: An Extension to the Session Initiation Protocol (SIP) for Symmetric Response Routing — IETF / RFC Editor · tier 1 standards and regulators · Section 4 Server Behavior
Cite this note
APA
WarmTransfer. (2026, September 25). SIP registration failures: source note sip-registration-failures-rport-server. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-registration-failures-rport-server
BibTeX
@misc{warmtransfer-claim-sip-registration-failures-rport-server,
title = {SIP registration failures: source note sip-registration-failures-rport-server},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-registration-failures-rport-server},
note = {Source note sip-registration-failures-rport-server, checked 2026-09-25}
}