48 Ports Gigabit PoE for downlink 4 Ports 10G SFP+ for uplink PoE IEEE802.3af/at options, power budget 370 W 6kV surge protection on all Gigabit Ethernet ports Physical stacking up to 9 switches ZTP (Zero-Touch Provisioning) Ethernet Ring Protection Switching (ERPS) IEEE 802.1ag for Connectivity Fault Management ITU-T Y.1731 for Delay Measurement Massages Manage through the Nuclias Network Controller. D-Link Corporation, No. 289, Sin Sin Road, Jhonghe City, Taipei County 235, Taiwan (R.O.C.), Podpora: https://www.dlink.com/cz/cs/support