D-Link 2-Port Optional Module for DES-6000, 1 Gbit/s, Gigabit Ethernet, 1000Base-LX, IEEE 802.3z, IEEE 802.3x, 2 MB, 2x Gigabit Ethernet ports D-Link 2-Port Optional Module for DES-6000. Data transfer rate: 1 Gbit/s, Data link protocols: Gigabit Ethernet, Cabling technology: 1000Base-LX. Internal memory: 2 MB. I/O ports: 2x Gigabit Ethernet ports