Hi
The answer for ur querry is that u need to have an IPLC between UK and India in place , this IPLC u can get from Service Provider like BT in UK and VSNL in India ,to terminate this IPLC u need Mux at both the ends.
Again in UK end all toll free calls will terminate to the mux through E1 provided by SP there and the calls will land to India to the ACD which will intelligently distribute it the call agents as per the defined business logic.