Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility Cross Cluster

Publisher

Cisco Systems

URL

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/cucm_b_feature-configuration-guide-for-15/cucm_mp_e07f13b5_00_extension-mobility-cross-cluster-12-0.html

Published

2026-09-16

Updated

unknown

Accessed

2026-09-24

HTTP status

200

License

Cisco documentation; all rights reserved; no-redistribution; short excerpts and locators only

Source notes citing this source

• EMCC setup requires bulk certificate management: each cluster exports its certificates (Certificate Type All) to the same SFTP server, the certificates are consolidated, and they are imported back into each cluster. in context
• Extension Mobility Cross Cluster (EMCC) gives users EM functionality while letting them move from their home cluster and log in to a temporary phone on a remote (visiting) cluster. in context
• The same phone (device name) must not be configured in two clusters for EMCC; otherwise login fails with duplicate device error 37. in context
• EMCC login requires the Enable Extension Mobility Cross Cluster check box for the user in the home cluster; login results 31 and 38 report it unchecked. in context
• EMCC login result 35 occurs when the home cluster has no entry for the visiting cluster. in context
• Phones in IPv6-only addressing mode do not support EMCC; IPv4 or dual-stack phones can be used. in context
• Under EMCC, E911 calls and local calls from the logged-in phone are routed to the local PSTN gateways. in context
• Unified CM supports a MaxPhones value of 60,000, and EMCC devices count double: Phones + (2 x EMCC devices) = MaxPhones. in context
• EMCC does not support the intercom feature. in context
• EMCC does not support Location-based call admission control but does support RSVP-based CAC. in context
• EMCC feature parameter defaults include Remote Cluster Update Interval 30 minutes (15 to 10080), Default Interval for Expired EMCC Device Maintenance 1440 minutes (10 to 1440), RSVP SIP Trunk KeepAlive Timer 15 seconds, and Enable All Remote Cluster Services When Adding A New Remote Cluster False. in context
• EMCC uses a PSTN Access SIP trunk so the visiting phone's outbound PSTN calls go out through gateways in the visiting cluster, and an RSVP Agent SIP trunk for RSVP-based call admission control. in context
• The EMCC region defaults are a maximum audio bit rate of 8 kbps (G.729), a maximum video call bit rate of 384 and link loss type Low Loss. in context
• For EMCC, the visiting cluster matches the phone's geolocation against configured geolocation filters to choose the roaming device pool that best matches. in context
• EMCC supports phones with secure or nonsecure phone security profiles, in clusters set to nonsecure or mixed mode, and cross-cluster security is provided by default. in context
• The EMCC task flow runs: EM services and phone service; device profiles and enabling EMCC for users; certificate export, consolidation and import; common device configuration and EMCC template; geolocation filter; EMCC feature parameters; intercluster SIP trunk; intercluster service profile; remote cluster services. in context
• The EMCC feature parameter Default TFTP Server for EMCC Login Device names the TFTP server that devices logging in through EMCC from a remote cluster should use; it has no default. in context
• 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. in context

Cite this source record

APA

WarmTransfer. (2026, September 16). Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility Cross Cluster. WarmTransfer. https://warmtransfer.net/knowledge/sources/cisco-cucm-fcg-15-emcc

BibTeX

@misc{warmtransfer-cisco-cucm-fcg-15-emcc,
  title  = {Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs - Extension Mobility Cross Cluster},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/sources/cisco-cucm-fcg-15-emcc},
  note   = {Cisco Systems, accessed 2026-09-24}
}