1)With SIP protocol; 2)Provide E1, FXO, FXS interface;but ... but also provide VoIP interface to IP network.NC-AD300E PBX has its powerful signaling protocol handling and exchanging capability, ... support: SS7,ISDN-PRI, Q.SIG, V5.2,R2*SIP Protocol*Codes: G.711-pcma, G.711-pcmu, G ... support throught TCP or UDP*Grouping switching management, have PBX function as below:-Pre-recording voice attendance-Busy, No ...