... backbone optical-fiber protection, “1+1” hand-in-hand protection, full protection, switchover delay of less than 50msSoftware functionsSupported network standardIEEE ... VLAN Stacking (QinQ)Flow controlSupporting HOL block prevention, half-duplex backpressure and full-duplex IEEE 802.3xARPSupportDHCPSupporting Client, Relay and ServerPort aggregationSupporting 802 ...