EMCC needs no more than two SIP trunks: one trunk can carry both PSTN access and RSVP agent services, or there can be one trunk for each.
Checked 2026-09-24
You do not need more than two SIP trunks for extension mobility cross cluster.
- Vendor
- Cisco
- Product
- Cisco Unified Communications Manager
- Subsystem
- emcc
- Deployment
- on-premises, multi-cluster
- Region
- not restricted
- Release range
- Release 15 and SUs, current as of 2026-09-24
- Checked
- 2026-09-24
Sources
- Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility Cross Cluster — Cisco Systems · tier 2 current vendor documentation · Configure an Intercluster SIP Trunk for Extension Mobility Cross Cluster
Cite this note
APA
WarmTransfer. (2026, September 24). Unified CM Extension Mobility and cross-cluster Extension Mobility: source note cucm-extension-mobility-emcc-two-trunks-max. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-extension-mobility-emcc-two-trunks-max
BibTeX
@misc{warmtransfer-claim-cucm-extension-mobility-emcc-two-trunks-max,
title = {Unified CM Extension Mobility and cross-cluster Extension Mobility: source note cucm-extension-mobility-emcc-two-trunks-max},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/cucm-extension-mobility-emcc-two-trunks-max},
note = {Source note cucm-extension-mobility-emcc-two-trunks-max, checked 2026-09-24}
}