Chapter 1 What’s New for FortiOS 5.0 : New features in FortiOS 5.0 Patch 2 : The SIP ALG can receive SIP traffic on multiple TCP and UDP ports
  
The SIP ALG can receive SIP traffic on multiple TCP and UDP ports
You also configure the SIP ALG to listen in two different TCP ports and two different UDP ports for SIP sessions. For example, if you receive SIP TCP traffic on port 5060 and 5064 and UDP traffic on ports 5061 and 5065, you can enter the following command to receive the SIP traffic on all of these ports:
config system settings
set sip-tcp-port 5060 5064
set sip-udp-port 5061 5065
end