SS7 to SIP Gateway, integration TDM and IP networks, TDM over IP, SIP trank, E1 stream, tdm switch over ip, 4 8 16 E1, SS7, ISDN PRI, V5.2, V5.1, R2 CAS, R2 MFC, R2 DTMF, voice codecs G.711, G.723, G.726, G.729