We have a client that uses Nortel VPN client to connect to his workplace. Problem is the Nortel VPN stops responding after 5 seconds.

It seems like the problem is with the masqurade rule, we tested it from our office where there is no internal PPPoEs or any firewalls. It only goes through 3 Mikrotik routerboards with the last one launcing the PPPoE to the internet(ofcause the last MT has a masqurade rule on). The MTU on that last PPPoE is 1492.

Other clients using Cisco VPN clients or PPTP/L2TP/OpenVPN vpns have no such problems. Also the client in question have no problems when he uses his cellfone to connect to the internet(that gets a public IP)

Any ideas what we can try to help him out?