Cisco Cisco Expressway
Task 8: Check the Message Size Limit on Unified CM
SIP messages for video are considerably larger than SIP messages for audio calls, in particular, when a Cisco
TelePresence Server is used in the video network.
TelePresence Server is used in the video network.
Ensure that the SIP Max Incoming Message Size on Unified CM is set to 11000:
1.
Go to System > Service Parameters.
2.
Select the appropriate server.
3.
Select Cisco CallManager (Active) as the service.
4.
Select Advanced.
5.
In the Clusterwide Parameters (Device – SIP) configure the field as follows:
SIP Max Incoming Message Size
11000
6.
Click Save.
Connecting Expressway to Unified CM Using TLS
These instructions explain how to take a system that is already configured and working using a TCP interconnection
between Expressway and Unified CM, and to convert that trunk to use TLS instead. This table summarizes the
process:
between Expressway and Unified CM, and to convert that trunk to use TLS instead. This table summarizes the
process:
Command or Action
Table 6 Overview of Tasks to Create SIP TLS Trunk Between Expressway and Unified CM
Ensure Certificate Trust Between Unified CM and Expressway
For Unified CM and Expressway to establish a TLS connection with each other:
■
Expressway and Unified CM must both have valid server certificates loaded (you must replace the
Expressway's default server certificate with a valid server certificate)
Expressway's default server certificate with a valid server certificate)
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Cisco Expressway with Microsoft Lync Deployment Guide