Source note · Early media and ringback behavior
RFC 3262 defines the PRACK method to acknowledge a reliable provisional response, with the RSeq header in the provisional response and the RAck header in the PRACK.
Checked 2026-09-24
- Vendor
- IETF
- Product
- SIP
- Subsystem
- reliable provisional responses
- Deployment
- any
- Region
- not restricted
- Release range
- RFC 3262
- Checked
- 2026-09-24
Sources
- RFC 3262: Reliability of Provisional Responses in the Session Initiation Protocol (SIP) — IETF / RFC Editor · tier 1 standards and regulators · Sections 6 and 7 (PRACK method; RSeq and RAck headers)
Cite this note
APA
WarmTransfer. (2026, September 24). Early media and ringback behavior: source note early-media-ringback-prack-rseq. WarmTransfer. https://warmtransfer.net/knowledge/claims/early-media-ringback-prack-rseq
BibTeX
@misc{warmtransfer-claim-early-media-ringback-prack-rseq,
title = {Early media and ringback behavior: source note early-media-ringback-prack-rseq},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/early-media-ringback-prack-rseq},
note = {Source note early-media-ringback-prack-rseq, checked 2026-09-24}
}