JMLing

Greetings, Maybe someone can help. My company recently had a DVR installation performed, here's the best bit... The install was partially finished and I've had to do the rest myself. I've configured what I believe is an AVD715D (8 Channel, MPEG-4 DVR Quick High-End Series). I've got it working perfectly via an external IP with port forwarding. My issue however is that due to company security policies it has to work over a secure vpn instead. The VPN is a branch office tunnel over ADSL between a Firebox Edge and a Firebox x700. The VPN works perfectly for everything else. I've set the DVR on the same range as the remote computers, same gateway, submask and DNS. At the remote site it works on the LAN perfectly however on the other side of the VPN I'm getting an error "Get Config Error!! Please try Again!!". From what I see in the logs there is nothing blocking the port and all responses are allowed. Any help / ideas would be much appreciated. Thank you. James Ling

After even deeper investigation I've found that the DVR is trying to transmit across the vpn with a mtu of 1460... however for it to work properly it needs to transmit with a mtu of 1364 (ssl vpn etc). Does anyone know how to change the MTU on this DVR ? AVD715D (8 Channel, MPEG-4 DVR Quick High-End Series)

Tried a sniffer... there were a few warnings but nothing associated with the vpn or dvr. After going through the logs though I noticed that after the connection is made a rst command is sent and then the connection restarts and it repeats.