在Asterisk1.6中似乎提供一个AMI指令实现回拔功能，就是通过指令让服务器分别拔打两个号码。
Asterisk.Api.Originate ori = new Asterisk.Api.Originate();
ori.Account = "30855";
ori.Channel = "SIP/100036";
ori.Context = "DLPN_DialPlan1";
ori.Exten = "1100002";
ori.Priority = "1";
ori.CallerID = "";
ori.Timeout = "30000";
ori.Send(callback）
http://www.voip-info.org/wiki/view/Asterisk+Manager+API+Action+Originate