I am trying to establish a VPN tunnel between these two devices, and I get 'No Matching SA found' error. The Checkpoint device is configured for automatic security settings, while the Digi device is configured for AES 256 bit, SHA 1, group 2 settings for both phase 1 and phase 2. The Digi device is behind the cellular carrier's NAT (It has an ip address of 10.168.x.x) Is it possible to establish a VPN in such conditions?