Asterix calling 2 numbers and make a conference

I need to configure a asterixNOW to when asked, call using VOIP to phones, my mother and my grandma and put they in conference. So pressing one button, my grandma can talk my mother as she was receiving a call, not needing to press numbers at the phone. ## Deliverables * the system must receive the #SIP I enter, and I don't know if I need 1 or 2 #SIPs for that