Source note · Expressway business-to-business calling

With the default Registered only mode, a B2B call between a Unified CM SIP user and an external H.323-only system through Expressways with no locally registered endpoint would probably not be interworked unless the mode is changed to On.

inferred · Checked 2026-09-25

Vendor: Cisco
Product: Cisco Expressway
Subsystem: interworking
Deployment: on-premises
Region: not restricted
Release range: X15.4
Status: inferred
Checked: 2026-09-25

Sources

Cisco Expressway Administrator Guide (X15.4) - Protocols — Cisco Systems · tier 2 current vendor documentation · Configuring H.323 and SIP Interworking

Cite this note

APA

WarmTransfer. (2026, September 25). Expressway business-to-business calling: source note expressway-b2b-calling-interworking-b2b-gap. WarmTransfer. https://warmtransfer.net/knowledge/claims/expressway-b2b-calling-interworking-b2b-gap

BibTeX

@misc{warmtransfer-claim-expressway-b2b-calling-interworking-b2b-gap,
  title  = {Expressway business-to-business calling: source note expressway-b2b-calling-interworking-b2b-gap},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/expressway-b2b-calling-interworking-b2b-gap},
  note   = {Source note expressway-b2b-calling-interworking-b2b-gap, checked 2026-09-25}
}

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