VoIP Calls disconnect after 15 Minutes with SonicWall

Found this on the Internet.

Basically from the comments I did the following:

I have found that SonicWalls NSA units have SPI and DPI causing major problems with VoIP.  Under Firewall Settings, go to settings and choose Maximium SPI Connections (DPI services disabled).  Also there is additional internal settings you can enable/disable by “\diag.html” (https://10.1.10.1/diag.html) .  Also under the Firewall Settings option, I would recommend increasing the Default UDP Connection Timeout to: 3600 seconds.

I also did the following:

Also, under “VoIP” settings, enable “Consistant NAT”.