Cisco Cisco Expressway
Protocol
Security
Service
SIP
TLS
Session establishment – Register, Invite etc.
HTTPS
TLS
Logon, provisioning/configuration, directory, visual voicemail
RTP
SRTP
Media - audio, video, content sharing
XMPP
TLS
Instant Messaging, Presence
Clustered Expressway systems and failover considerations
You can configure a cluster of Expressway-Cs and a cluster of Expressway-Es to provide failover
(redundancy) support as well as improved scalability.
(redundancy) support as well as improved scalability.
contained in Configure DNS for Cisco Jabber.
Note that when discovering Unified CM and IM&P servers on Expressway-C, you must do this on the master
peer.
peer.
Media encryption
Media encryption is enforced on the call legs between the Expressway-C and the Expressway-E, and
between the Expressway-E and endpoints located outside the enterprise.
between the Expressway-E and endpoints located outside the enterprise.
The encryption is physically applied to the media as it passes through the B2BUA on the Expressway-C.
Advanced Expressway-C configuration
This section covers the advanced Unified Communications settings that can be configured on Expressway-
C.
C.
Credential caching intervals
The Expressway caches endpoint credentials which have been authenticated by Unified CM. The caching of
credentials reduces the frequency with which the Expressway has to submit endpoint credentials to Unified
CM for authentication, and thus improves system performance.
credentials reduces the frequency with which the Expressway has to submit endpoint credentials to Unified
CM for authentication, and thus improves system performance.
To configure the caching settings, go to
Configuration > Unified Communications
and then click Show
advanced settings.
The Credentials refresh interval specifies the number of minutes for which endpoint credentials are cached
in the Expressway database. The default is 480 minutes.
in the Expressway database. The default is 480 minutes.
The Credentials cleanup interval specifies the frequency with which the Expressway database runs a
cleanup process to remove expired credentials. In large deployments, a regular cleanup process helps to
maintain the system's performance. The default is 720 minutes.
cleanup process to remove expired credentials. In large deployments, a regular cleanup process helps to
maintain the system's performance. The default is 720 minutes.
Unified Communications Mobile and Remote Access via Cisco Expressway Deployment Guide (X8.5.1)
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Additional information