Source note · SIP registration failures
If a UA's registration refresh or keep-alive interval is longer than the NAT or firewall binding timeout, REGISTER can keep succeeding while inbound requests to the registered contact fail between refreshes.
inferred · Checked 2026-09-25
- Vendor
- not restricted
- Product
- SIP
- Subsystem
- nat-traversal
- Deployment
- any
- Region
- not restricted
- Release range
- current as of 2026-09-25
- Status
- inferred
- Checked
- 2026-09-25
Sources
- RFC 5626: Managing Client-Initiated Connections in the Session Initiation Protocol (SIP) — IETF / RFC Editor · tier 1 standards and regulators · Section 3 Overview (UAs behind NAT cannot receive inbound connections); Section 4.4 keep-alives
Cite this note
APA
WarmTransfer. (2026, September 25). SIP registration failures: source note sip-registration-failures-refresh-vs-nat-timeout. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-registration-failures-refresh-vs-nat-timeout
BibTeX
@misc{warmtransfer-claim-sip-registration-failures-refresh-vs-nat-timeout,
title = {SIP registration failures: source note sip-registration-failures-refresh-vs-nat-timeout},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-registration-failures-refresh-vs-nat-timeout},
note = {Source note sip-registration-failures-refresh-vs-nat-timeout, checked 2026-09-25}
}