Call conference

Hi all

I want to enable conference for a n external number.ie Three way conference.

Suppose a person (A) calls me(B) then I tlks to him and calls third one © through

attended transfer or other channel in xlite. After talking with C I want to enable

conference so that A,B & C can talk each other and be in a conference.

Is there any way for this…Please give me an answer…

I am able to do attended transfer using *2 feature …but when B hangs up

A & C will be connected, but B can not join in conference…please help me…