Communications problems...

[ataubman]

But, I was hoping that the behavior of the servers involved might give me an idea of what kind of communication between the servers is being blocked by the gateways.

Well, pretty clearly eDirectory is one kind of communication that's dropping out (again, I'm not seeing that it's being blocked per se, as it gets through initially). As far as other behaviour of the server, what else have you checked? Timesync? Pings? SLP? What ports have you told them to allow through?

If that doesn't cover it, to be honest I'm really not sure what kind of thing you are after here. Can't you just say to the VPN vendor "why are our communications dropping out after 3 minutes? That didn't used to happen" ?