we are using panasonic ip handsets

we have solved our problem by adding the ip of the TDE to the DMZ on the 3300 , no probs at all now

That makes sense, but it leaves your TDE a bit exposed to the "open" if it is in the DMZ?

We are still working on the spoke-spoke approach, but haven't had too much time this week. Will let you know how we get on.

we were advised by draytek to put the tde on the dmz

OK, that makes sense, or at least that will make it all work, but I am wondering if they suggested that as it won't work spoke-spoke and this is the work around?

Thanks again - Terry