Source note · SIP retransmission timers and transaction state
Four timers are scoped to an unreliable transport and become 0 on a reliable one: A and E do not retransmit at all and D I J and K wait 0 seconds instead of their unreliable values.
Checked 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
- Checked
- 2026-09-15
Sources
- RFC 3261 — SIP: Session Initiation Protocol — IETF / RFC Editor · tier 1 standards and regulators · RFC 3261 appendix A, the timer table
Cite this note
APA
WarmTransfer. (2026, September 15). SIP retransmission timers and transaction state: source note siprt-transport-decides-whether-a-timer-runs. WarmTransfer. https://warmtransfer.net/knowledge/claims/siprt-transport-decides-whether-a-timer-runs
BibTeX
@misc{warmtransfer-claim-siprt-transport-decides-whether-a-timer-runs,
title = {SIP retransmission timers and transaction state: source note siprt-transport-decides-whether-a-timer-runs},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/siprt-transport-decides-whether-a-timer-runs},
note = {Source note siprt-transport-decides-whether-a-timer-runs, checked 2026-09-15}
}