A back-to-back user agent receives a request as a UAS and generates its own requests as a UAC, and unlike a proxy it maintains dialog state.

Checked 2026-09-24

Vendor
IETF
Product
SIP
Subsystem
B2BUA
Deployment
any
Region
not restricted
Release range
RFC 3261
Checked
2026-09-24

Sources

Cite this note

APA

WarmTransfer. (2026, September 24). Carrier escalation evidence packages: source note carrier-escalation-evidence-b2bua-definition. WarmTransfer. https://warmtransfer.net/knowledge/claims/carrier-escalation-evidence-b2bua-definition

BibTeX

@misc{warmtransfer-claim-carrier-escalation-evidence-b2bua-definition,
  title  = {Carrier escalation evidence packages: source note carrier-escalation-evidence-b2bua-definition},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/carrier-escalation-evidence-b2bua-definition},
  note   = {Source note carrier-escalation-evidence-b2bua-definition, checked 2026-09-24}
}

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