1.16FXS interfaces 2.Standard SIP V2.0, MGCP V1.0 (option)protocols 3.T.38 FAX 4.SNMP 1/2FXS/4FXS/4FXO,8FXS/8FXO,16FXS/16FXO,32FXS multiple interfacesStandard SIP V2.0, MGCP V1.0 protocolsStandard G.711A/U,G.723.1,G.729A/B,G.168,PCM A/U codeCall forwarding, Call hold, Caller ID, DND standard voice serviceBusy tone, Power-down protection , Fault identificationMany users sharing ADSL linesDAG ...