... supply board)-12*slot for various data/voice interface(with backup main control board) or 13*slot(without backup main control board)8*E1 ... per E1 board, maximum occupy 8 slotsVoice:16*FXS,16*FXO,8*E&M,8*MS,8*MSA,4*HFA ... to seven km by the ISDN 2B+D Data interface board;Possessing 10Base-T Ethernet bridge which supports VLAN transparent cutting ...