A setting on SIP (Session Initiation Protocol) phones identifies the location of the SIP phone configuration file. The setting points to a Web server, usually the SIP Enablement Server (SES).
On the Web server is the 46xxsettings.txt file, which contains configuration settings to be sent to each SIP phone.
You should update the 46xxsettings.txt file to identify the IP address of the proxy agent computer.
To update the 46xxsettings.txt file:
Open the file in a text editor.
Add the following line of text:
SET RTCPMON IP address
where IP address is the IP address of the proxy agent computer.
Reboot your SIP phones so that they pick up the new configuration setting.