... , adaptive and loopback•Provide 2 STM-1 optical ports , Support 1 + 1 protection•Ethernet built-in layer 2 switch, support VLAN802.1Q ... and drifting•Resist to packet loss, with frame synchronization protection,•Enough jitter buffer to resist packet delay variation (PDV)• ... + 1 backupSpecification:Capacity2 STM-1 optical port (1+1 protection), 5GE electronically port , 1GE optical port and 1 external ...