Hi Gulzar,
The Welltech gateways support H.450 services including call transfer. They also support dynamic CODEC negotiation so all those horrible CODEC mismatch issues are a thing of the past.
To make things even better they are H.323 and SIP compliant and under half the price of a Quintum equivalent.
Hope this helps
Mat Hitchcock
mhitchcock@blue-lava.co.uk