... .726, G.729, GSM, SPEEX GSM IP PBX ---ZX50-AG42ZX50-AG42 IP PBX Description: ZX50 IP phone system is SIP based and optimized ... to run on a variety of VoIP applications, it provides IP-based communications, voice conferencing; it also supports paging /intercom, call ... ,G.711-Alaw,G.726,G.729 GSM,SPEEX,H.261,H.263,H.263+,H.264 Black List Phone Book DISA(Direct Inward System ...