How to configure SIP trunking on fortinet fortigate firewalls for VoIP phones

Is your VOIP phone not working in your network over you fortigate firewall? This could be your fix.When configuring SIP on a FortiGate,  it is recommended to disable the SIP session-helper and work with the SIP Application Layer Gateway to ensure compatibility across SIP systems.

Login to your fortinet firewall on the browser and open the CLI in the dashboard.

1- Check the Session-helper number:

FGT# show system session-helper

edit 12 (1)

set name sip

set port 5060

set protocol 17

next

(1) Use this ID for the next step

2- then remove this session-helper:

FGT# config system session-helper

FGT#(session-helper) delete 12

FGT#(session-helper) end3 – Reboot the FortiGate in order for the above changes to take effect

3 – Reboot the FortiGate in order for the above changes to take effect

4 – Create a Protection Profile with SIP enabled

Instruction for FortiOS 4.0 and above

 1 – Enter the following command to add an application control list called App_list_SIP, enable SIP support in the list, and limit REGISTER and INVITE requests to 100 requests per second per firewall policy (values are given as an example).

config application list

edit App_list_SIP

config entries

edit 1

set category voip

set application SIP

set register-rate 100

set invite-rate 100

end

end

2 – Enter the following command to add the App_list_SIP to a protection profile called SIP_Profile.

config firewall profile

edit SIP_Profile

set application-list-status enable

set application-list App_list_SIP

end