28-Port Gigabit Smart Switch with 4 SFP slots - 24 x 10/100/1000Mbps Auto-Negotiating Ports plus 4 x SFP Slot - RJ 45 Console Port - Smart Console Utility, web based management, compact CLI - Advance power saving features - Fanless design - Half-/Full-Duplex, auto-negotiation, Auto MDI/MDIX - IEEE 802.3x Flow Control - 802.3ad Link Aggregation - VLAN Trunking - Switching Capacity 20Gbps - Max packet forwarding rate 14.88Mpps - Jumbo frame 9,216 - Asymmetric VLAN, Auto Voice VLAN - Protocol based VLAN - MAC based VLAN - 802.1p priority queues - MAC/IP filtering - MAC/IP-based ACL - ACL flow based mirroring - 802.1X port-base Access Control, Port Security - Static Routing, 64 IPv4 static routes, 32 IPv6 static routes - 802.3ah Ethernet Link OAM, D-link Unidirectional Link Detection (DULD), Dying Gasp, DDM - Ethernet Ring Protection Switching (ERPS) - D-Link Safequare Engine - D-View 6.0 support - 19" Rackmount Installation - Surge protection - Firmware release 7 not backward compatible to hardware version A1 - optional redundant power supply DPS-200A (requires DPS-CB150-2PS)