Source note · Hold resume and conference signaling

RFC 6337 says that when both sides are on hold each side must clear its own hold state and the first UA to come off hold sends an offer with sendrecv.

Checked 2026-09-24

If UA1 is first to go off hold, it will then send an offer with "a=sendrecv" attribute.

Vendor: IETF
Product: SIP
Subsystem: resume
Deployment: any
Region: not restricted
Release range: RFC 6337 as published
Checked: 2026-09-24

Sources

RFC 6337: Session Initiation Protocol (SIP) Usage of the Offer/Answer Model — IETF / RFC Editor · tier 1 standards and regulators · Section 5.3 Hold and Resume of Media

Cite this note

APA

WarmTransfer. (2026, September 24). Hold resume and conference signaling: source note hold-resume-conference-6337-resume-sendrecv. WarmTransfer. https://warmtransfer.net/knowledge/claims/hold-resume-conference-6337-resume-sendrecv

BibTeX

@misc{warmtransfer-claim-hold-resume-conference-6337-resume-sendrecv,
  title  = {Hold resume and conference signaling: source note hold-resume-conference-6337-resume-sendrecv},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/hold-resume-conference-6337-resume-sendrecv},
  note   = {Source note hold-resume-conference-6337-resume-sendrecv, checked 2026-09-24}
}

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