... :VoIP Media Trunk Gateway contains a total of four models, MG800 ... G.964, G.965)·VoIP protocol support: -SIP(RFC3261, RFC3362(T.38), RFC2833(DTMF)); -Code: G.711µ-Law and A-Law, G.711 Appendix 1,G ... .723.1 and G.723.1 Annex A, G.729 Annex A and Annex B,G ... .726;·Echo Cancellation: G ...