Layer two commercial switch, Supports IEEE802.3, IEEE802.3u and IEEE802.3X ,IEEE802.3ab standards , Port 1-16: 16 × RJ-45 10/100/1000 Mbps (PoE); Port 17-18: 2 × RJ-45 10/100/1000 Mbps (uplink); Port 19-20: 2 ×SFP 1000 Mbps (uplink) , Port 1-2 ≤ 90 W, Port 3-16 ≤ 30 W, total ≤ 240 W, internal power supply, metal enclosure, desktop/ rackmount , long Distance PoE supported.