SIP OPTIONS (RFC 3261 section 11) queries a peer's capabilities and may be sent outside a dialog; the capabilities come back in the 200 OK's Allow and Accept headers.

Checked 2026-09-25

Vendor
IETF
Product
SIP
Subsystem
keepalive
Deployment
any
Region
not restricted
Release range
RFC 3261
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). SIP trunk carrier turn-up and acceptance testing: source note sip-trunk-carrier-turn-up-rfc3261-options. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-trunk-carrier-turn-up-rfc3261-options

BibTeX

@misc{warmtransfer-claim-sip-trunk-carrier-turn-up-rfc3261-options,
  title  = {SIP trunk carrier turn-up and acceptance testing: source note sip-trunk-carrier-turn-up-rfc3261-options},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-trunk-carrier-turn-up-rfc3261-options},
  note   = {Source note sip-trunk-carrier-turn-up-rfc3261-options, checked 2026-09-25}
}

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