Technical Tip: How to apply VoIP profile to policy where no SIP inspection is required

[JHelio]

Description	This article describes how to apply VoIP profile where SIP inspection is not required for specific traffic crossing IPv4 policy. The latest FortiGate versions have by default VoIP SIP ALG enabled globally and sometimes the FortiGate needs to handle more than one VoIP solutions where one solution will need SIP ALG active and other VoIP solutions will not be required. Default FortiGate configuration: config system settings     set default-voip-alg-mode proxy-based  <----- SIP ALG enabled. end Note: If ALG mode is set in Kernel mode, Firewall policy is still required in Proxy mode to use a different VOIP profile. If a specific traffic flow requires to pass without SIP ALG inspection active, this can also be accomplished by adding the following VoIP profile to the IPv4 policy which allows this traffic. Note that the VoIP profile that is applied has the SIP inspection disabled. If such a profile is not used, FortiGate will detect the SIP traffic and apply the 'default' VoIP profile even if not applied in the policy: Create VoIP profile with no SIP inspection by CLI: config voip profile     edit "VoIP_ALG_Off"     config sip         set status disable <----- Disable SIP inspection.         set rtp disable <----- Avoid RTP pinholes creation.      end next Assign such VoIP profile to the policy desired: By CLI: config firewall policy     edit 1         set name "disable VoIP"         set utm-status enable         set voip-profile "VoIP_ALG_Off" <----- VoIP profile assigned. next Note: Enable VoIP feature from System -> Feature Visibility -> VoIP.
Scope	FortiGate.
Solution	Having VoIP profiles where one has SIP ALG disabled, allows one to decide which traffic needs SIP inspection and which does not at the policy level.