Source note · SIP call forwarding and routing loops
RFC 7332 recommends that B2BUAs implement the Via-based loop-detection mechanism that RFC 5393 defines for proxies, and requires them to copy any received Max-Breadth header field to the requests they generate.
Checked 2026-09-25
- Vendor
- IETF
- Product
- SIP
- Subsystem
- B2BUA loop detection
- Deployment
- any
- Region
- not restricted
- Release range
- RFC 7332 (August 2014) onward
- Checked
- 2026-09-25
Sources
- RFC 7332: Loop Detection Mechanisms for Session Initiation Protocol (SIP) Back-to-Back User Agents (B2BUAs) — IETF / RFC Editor · tier 1 standards and regulators · Section 3 B2BUA Behavior (Via loop detection; Max-Breadth)
Cite this note
APA
WarmTransfer. (2026, September 25). SIP call forwarding and routing loops: source note sip-forwarding-loops-b2bua-via-loop-rec. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-forwarding-loops-b2bua-via-loop-rec
BibTeX
@misc{warmtransfer-claim-sip-forwarding-loops-b2bua-via-loop-rec,
title = {SIP call forwarding and routing loops: source note sip-forwarding-loops-b2bua-via-loop-rec},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-forwarding-loops-b2bua-via-loop-rec},
note = {Source note sip-forwarding-loops-b2bua-via-loop-rec, checked 2026-09-25}
}