While we were working on Unified Messaging configuration and troubleshooting , a question was raised that if Exchange team can change the default SIP listening port for the server ??
Answer is yes we can change the Port , Default listening port is 5060 & can be modified.
Telnet on Port 5060 just to check:(it get connected)
Although there are some ports on UM server that can't be changed but this one can be changed with below PowerShell command line:
Set-UmServer -Identity "Server" -SipTcpListeningPort "port"
After executing this Command in Exchange Management Shell , you will get a warning to restart the Unified Messaging Service so that changes can take effect.
Go ahead & restart the service.
Now again do the Telnet Test as shown above to verify the connectivity on the port you changed.
Please check the eventvwr as well so that there are no errors of conflict, as first time When I changed it , I used 5065 as suggested by Voice Team but that was already in use by UM worker process so after service restart that process failed :)
Note: - Above command was used on Exchange 2010 UM server, for other versions cmdlet might have changed.