Because Cisco documents Error 207 both as Device Name Empty (wrong URL) and, in the Release 15 guide, as EM Service Connection Error, a 207 on a Release 15 phone should be checked against both the service URL and the state of the Cisco Extension Mobility service.
inferred · 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
- Status
- inferred
- 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 > Device Name Empty; EM Service Connection Error
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting Extension Mobility login failures in Unified CM: source note cucm-extension-mobility-troubleshooting-inf-207-ambiguous. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-extension-mobility-troubleshooting-inf-207-ambiguous
BibTeX
@misc{warmtransfer-claim-cucm-extension-mobility-troubleshooting-inf-207-ambiguous,
title = {Troubleshooting Extension Mobility login failures in Unified CM: source note cucm-extension-mobility-troubleshooting-inf-207-ambiguous},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/cucm-extension-mobility-troubleshooting-inf-207-ambiguous},
note = {Source note cucm-extension-mobility-troubleshooting-inf-207-ambiguous, checked 2026-10-02}
}