/mcpMobile and Remote Access Prerequisites Cisco Unified Communications Manager Requirements The following requirements apply: • If you are deploying multiple Unified Communications Manager clusters, set up an ILS network. • Mobile and Remote Access requires that you set up NTP servers for your deployment. Make sure that you have NTP servers deployed for your network and Phone NTP References for SIPendpoints. • If you are deploying ICE for media path optimization, you will need to deploy a server that can provide TURN and STUN services. DNS Requirements For the internal connection to Cisco Expressway, configure the following locally resolvable DNS SRV that points to Unified Communications Manager: _cisco-uds._tcp<domain> You must create internal DNS records, for both forward and reverse lookups, for all Unified Communications nodes used with Mobile and Remote Access. This allows Expressway-C to find the nodes when IP addresses or hostnames are used instead of FQDNs. Make sure that the SRV record is not resolvable outside of the local network. Cisco Expressway Requirements This feature requires you to integrate Unified Communications Manager with Cisco Expressway. For Cisco Expressway configuration details for Mobile and Remote Access, refer to the Mobile and Remote Access Through Cisco Expressway Deployment Guide. The minimum Expressway release for Mobile and Remote Access Access Policy support with Cisco Jabber is X8.10. Certificate Prerequisites You must exchange certificates between Unified Communications Manager, the IM and Presence Service, and Cisco Expressway-C. Cisco recommends that you use CA-signed certificates with the same CA for each system. In this case: • Install the CA root certificate chain on each system (for Unified Communications Manager and the IM and Presence Service Service install the certificate chain to the tomcat-trust store). • For Unified Communications Manager, issue a CSR to request CA-signed tomcat (for AXL and UDS traffic) and Cisco CallManager (for SIP) certificates. • For the IM and Presence Service Service, issue a CSR to request CA-signed tomcat certificates. If you use different CAs, you must install each CA's root certificate chain on Unified Communications Manager, IM and Presence Service Service, and Expressway-C. Note Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs 71 Remote Worker Features Mobile and Remote Access Prerequisites