Fortigate drops ingoing RTP connection after exactly 15 minutes
Incoming calls stop transmitting sound at exactly the 15 minute mark. the call timer counts as usual and stops as usual if one of the call members hangs up.
The SIP trunk works fine. It sends the "Re-Invite" as normal and gets an "OK" back as usual.
The RTP session seems to drop after the 15 minute mark.
My SIP provider told me to delete the SIP session helper and disable the SIP ALG and RTP processor.
I have also looked up if there is a session TTL or UDP idle timer that gets in the way but the timings doesn't seem to correlate.
Is there another TTL or timeout setting I'm missing?
The ports for the RTP sessions go from 7000-16511.