|Description||This article describes methods to choose SIP-ALG and Session Helper.|
|Scope||SIP ALG/Session Helper.|
By default, FortiGate is using SIP ALG to process SIP traffic however some SIP providers recommend disabling SIP ALG in the firewall.
Proxy-based – default SIP ALG mode
Below are points that need to be understood:
If proxy-based is selected which is a default mode, then no matter if session helper is configured, ALG mode supersedes and session helper is doing nothing.
- For traffic inspected by a helper, debug flow shows:
# diagnose debug application im 31