Chapter 1 What’s New for FortiOS 5.0 : Security Features : New SIP ALG features
  
New SIP ALG features
FortiOS 5.0 includes the following new SIP ALG features:
Inspecting SIP over SSL/TLS (secure SIP)
Opening and closing SIP via and record-route pinholes
Adding the original IP address and port to the SIP header after NAT