The Expressway-C neighbor zone destination port must match the incoming port set in the Unified CM SIP trunk security profile; a mismatch causes Unified CM to drop the TCP session on inbound B2B calls.
Checked 2026-09-25
- Vendor
- Cisco
- Product
- Cisco Expressway with Cisco Unified CM
- Subsystem
- neighbor zone
- Deployment
- on-premises
- Region
- not restricted
- Release range
- Expressway X8.1.1 or later
- Checked
- 2026-09-25
Sources
- Configure Business to Business Audio/Video Calls through Expressway — Cisco Systems · tier 2 current vendor documentation · Configure > Expressway-C > Neighbor Zone to CUCM
Cite this note
APA
WarmTransfer. (2026, September 25). Setting up business-to-business calling on Cisco Expressway: source note expressway-b2b-setup-neighbor-port-match. WarmTransfer. https://warmtransfer.net/knowledge/claims/expressway-b2b-setup-neighbor-port-match
BibTeX
@misc{warmtransfer-claim-expressway-b2b-setup-neighbor-port-match,
title = {Setting up business-to-business calling on Cisco Expressway: source note expressway-b2b-setup-neighbor-port-match},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/expressway-b2b-setup-neighbor-port-match},
note = {Source note expressway-b2b-setup-neighbor-port-match, checked 2026-09-25}
}