手机加密通话软件源码，通过GSM网络的CSD信道传输数据据，与VOIP不同，无须后台就能实现点对点呼叫 已通过测试。 -The phone encryption call software source code, the CSD channel to transfer data through the GSM network, according to, and VOIP, no background will be able to achieve point-to-point call