https://support.sophos.com/support/s/article/KB-000035917?language=en_US

Overview

Sophos Firewall supports Session Initiation Protocol (SIP) for multimedia communications like VOIP.


The SIP Module is turned on by default and provides the following functions for SIP traffic:

 

  • Works on TCP and UDP port 5060.
  • NATs local IP addresses to public IP addresses updating the SIP header.
  • Enables a dynamic voice channel by setting up an expected voice connection in the Firewall.

Applies to the following Sophos products and versions:

Sophos Firewall

 

Turn the SIP module on or off

  1. Sign in to the command line using Telnet or SSH. You can also access it from admin > Console in the upper right corner of the web admin console.
  2. Choose option 4. Device Console.
  3. Run either of the below commands:
     
    • console> system system_modules sip unload
    • console> system system_modules sip load
  4. Note: The commands are persistent even if the Sophos Firewall is rebooted.
     
  5. To confirm the status, run the below command:

    console> system system_modules show

    tidy_fix_alt

Use a custom port

If you are using a custom port for SIP communication and you would like to load the same port under the Sophos helper module, run the below command:


console> system system_modules sip load ports <custom_port>