... There are three different models with 2*E1/T1, 4*E1/T1, and 8*E1/T1. It supports SIP-T/SIP/H ... 45)Auto adaptedSupportedE1/T1 InterfaceNumber of Interfaces2 / 4 /8* E1/T1, RJ48 or G.703 optionalSignals & ProtocolsPRI SignalingProtocols compliantE1 PRI ... , ANSI, ETSI, JTC(Japan), ITU-China, ISUP/TUPMultiple E1 groupSupportedChina SS7 compatibilityChinese mainland and Hong KongVoice & FAXG.711A/USupportedG ...