All call handling actions (answer, hold. Initiate transfer, etc.)are performed on the SIP endpoint

All call handling actions (answer, hold, initiate transfer, etc.) are performed on the same PC (no Hardwareendpoint can be used)

A T-lib client such as Agent Desktop can control a call which is actually between other parties such as sipendpoints

Both, SIP endpoint and T-lib client such as Agent Desktop has to be integrated in one application