... voice processing(G.711,G.726,G.729a/b,G.723,G.728,iLBC), echo cancellation, ... of long-distance calls can be controlled by the phone; ·Complete call functions,it can provide several ... in SIP messages) RFC3372(SIGTRAN and SIP-T) RFC2327(sdp) RFC3398(ISUP-SIP Mapping) RFC3261(sip) RFC5806(Diversion Indication in SIP) RFC2833 ... Annex A, G.729 Annex A and Annex B, G.726,GSM,ARM,ILBCFax ProtocolT30, T38 and ...