Claim record · SIP retransmission timers and transaction state
Timer H sets the wait for an acknowledgement at 64 times the round trip estimate and its expiry is what ends a server transaction that never received one.
fact · verified 2026-09-15
- Vendor
- IETF
- Product
- Session Initiation Protocol
- Subsystem
- transaction timers
- Deployment
- not restricted
- Region
- not restricted
- Release range
- current as of 2026-09-15
- Status
- fact
- Confidence
- 0.90
- Verified
- 2026-09-15
Sources
- RFC 3261 — SIP: Session Initiation Protocol — IETF / RFC Editor · tier 1 standards and regulators · RFC 3261 sections 17.2.1 and appendix A
Cite this claim
APA
WarmTransfer. (2026, September 15). SIP retransmission timers and transaction state: claim siprt-timer-h-is-the-ack-deadline. WarmTransfer. https://warmtransfer.net/knowledge/claims/siprt-timer-h-is-the-ack-deadline
BibTeX
@misc{warmtransfer-claim-siprt-timer-h-is-the-ack-deadline,
title = {SIP retransmission timers and transaction state: claim siprt-timer-h-is-the-ack-deadline},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/siprt-timer-h-is-the-ack-deadline},
note = {Claim siprt-timer-h-is-the-ack-deadline, verified 2026-09-15}
}