Let me first say, I'm new here so please be patient.
We have a several SonicWall TZ 190 establishing VPN tunnels with a ASA5520. Pericodically random VPN tunnels will drop and can not re-establish a connection. In order to re-establish the dropped VPN tunnel, our firewall folks manually drop all VPN tunnels connected to the ASA (they use to physically power cycle the ASA). They claim this is the only way to resolve the problem and since the SonicWall Life Time seconds for Phase 1 and 2 are set to 28800, they reset the tunnels every 8 hours. Additionally, they claim that SonicWall IPSEC is different that Cisco IPSEC which is the main problem. Hence they are requesting a SONICWAll VPN concentrator... I think that is BS and want to get to the root cause of the problem.
Any suggestions on where to start and possible resolutions?