Source note · Troubleshooting Cisco IP phone registration
MRA endpoints can fail to register if a SIP trunk exists between Unified CM and Expressway-C using the same listening port as SIP line registrations; the trunk needs a different listening port on Unified CM.
Checked 2026-09-24
- Vendor
- Cisco
- Product
- Expressway
- Subsystem
- MRA registration
- Deployment
- on-premises
- Region
- not restricted
- Release range
- X15.2
- Checked
- 2026-09-24
Sources
- Mobile and Remote Access Through Cisco Expressway Deployment Guide (X15.2) - MRA Troubleshooting — Cisco Systems · tier 2 current vendor documentation · MRA Troubleshooting > Registration failures > SIP trunk between Unified CM and Expressway-C
Cite this note
APA
WarmTransfer. (2026, September 24). Troubleshooting Cisco IP phone registration: source note cisco-phone-registration-troubleshooting-mra-trunk-port. WarmTransfer. https://warmtransfer.net/knowledge/claims/cisco-phone-registration-troubleshooting-mra-trunk-port
BibTeX
@misc{warmtransfer-claim-cisco-phone-registration-troubleshooting-mra-trunk-port,
title = {Troubleshooting Cisco IP phone registration: source note cisco-phone-registration-troubleshooting-mra-trunk-port},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/cisco-phone-registration-troubleshooting-mra-trunk-port},
note = {Source note cisco-phone-registration-troubleshooting-mra-trunk-port, checked 2026-09-24}
}