In RFC 3261, the timeout for a non-INVITE client transaction (Timer F) is 64*T1, and T1's default is 500 ms.

Checked 2026-09-24

Vendor
IETF
Product
SIP
Subsystem
transaction layer
Deployment
any
Region
not restricted
Release range
RFC 3261 (June 2002)
Checked
2026-09-24

Sources

Cite this note

APA

WarmTransfer. (2026, September 24). SIP OPTIONS pings and trunk keepalives: source note sip-options-keepalive-rfc3261-timer-f. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-options-keepalive-rfc3261-timer-f

BibTeX

@misc{warmtransfer-claim-sip-options-keepalive-rfc3261-timer-f,
  title  = {SIP OPTIONS pings and trunk keepalives: source note sip-options-keepalive-rfc3261-timer-f},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-options-keepalive-rfc3261-timer-f},
  note   = {Source note sip-options-keepalive-rfc3261-timer-f, checked 2026-09-24}
}

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