With TLS verify On between Expressway-C and Unified CM, both servers' certificates must carry both client and server authentication usage, otherwise the TLS handshake fails.
Checked 2026-09-25
- Vendor
- Cisco
- Product
- Cisco Expressway with Cisco Unified CM
- Subsystem
- certificates
- Deployment
- on-premises
- Region
- not restricted
- Release range
- written against X8.x; not re-validated on X15
- Checked
- 2026-09-25
Sources
- Troubleshoot Most Common Issues for Business to Business Calls Through Expressway — Cisco Systems · tier 2 current vendor documentation · Issue: TLS verify on / certificate attributes
Cite this note
APA
WarmTransfer. (2026, September 25). Setting up business-to-business calling on Cisco Expressway: source note expressway-b2b-setup-cert-client-server-auth. WarmTransfer. https://warmtransfer.net/knowledge/claims/expressway-b2b-setup-cert-client-server-auth
BibTeX
@misc{warmtransfer-claim-expressway-b2b-setup-cert-client-server-auth,
title = {Setting up business-to-business calling on Cisco Expressway: source note expressway-b2b-setup-cert-client-server-auth},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/expressway-b2b-setup-cert-client-server-auth},
note = {Source note expressway-b2b-setup-cert-client-server-auth, checked 2026-09-25}
}