In Unified CM 15, an HTTP Error (503) on the phone when using Extension Mobility means the Cisco IP Phone Services or Cisco Extension Mobility Application service should be checked to confirm it is running.
Checked 2026-10-02
- Vendor
- Cisco
- Product
- Cisco Unified Communications Manager
- Subsystem
- Extension Mobility
- Deployment
- on-premises
- Region
- not restricted
- Release range
- 15 and SUs
- Checked
- 2026-10-02
Sources
- Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility — Cisco Systems · tier 2 current vendor documentation · Troubleshooting Extension Mobility > HTTP Error
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting Extension Mobility login failures in Unified CM: source note cucm-extension-mobility-troubleshooting-http-503-services. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-extension-mobility-troubleshooting-http-503-services
BibTeX
@misc{warmtransfer-claim-cucm-extension-mobility-troubleshooting-http-503-services,
title = {Troubleshooting Extension Mobility login failures in Unified CM: source note cucm-extension-mobility-troubleshooting-http-503-services},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/cucm-extension-mobility-troubleshooting-http-503-services},
note = {Source note cucm-extension-mobility-troubleshooting-http-503-services, checked 2026-10-02}
}