I tried, without sucess. But was a close call.
What I did manage was to make the Webswitch to connect like a champ to Quintum A200.
But not with the Quintum A400 gatekeeper or gateway.
Did not tried too hard either.
Also, they work like a champ from one Ercsson box to another.
The easiest box to setup that I found so far. About 5 minutes from the box to first call.