19 inches wide and 6U high, with 14×5/6/10/12/15 unit cards for total 210 channels of max accommodation. Interfaces: FXS, FXO, 2/4WE & M, V11, V24/RS232, etc.. Also supporting NX64Kbit/Sv. 35 and Ethernet.   All modules are hot-swap. 4×E1 for each 4E1 card, 64E1 for max E1 load. Auto switch between E1 interfaces as a key feature: When an error occurs on a E1, traffic will be switched to another E1 as pre-programmed.