With IPHost Network Monitor you can run simple snmp requests against a Fortinet device in your network.
fnNidsSigUserDefProto
fn Nids Sig User Def Protocol
1.3.6.1.4.1.12356.5.1.3.1.3
User defined signature protocol: tcp/udp
Back to FORTINET-MIB MIB page.
IPHost Network monitor allows you to monitor fnNidsSigUserDefProto on Fortinet device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Fortinet WAN extenders right now.