black box LB308A 
型号： LB308A 
产品描述:10BASE-T/100BASE-TX Hardened Ethernet Extender Switch, 8-Port
Further Details
Supports IP multicast filtering through IGMP snooping.
Complies with NEMA TS1 and TS2 environmental requirements for traffic 
equipment.
Supports port-based VLAN and IEEE 802.1q VLAN tagging and GVRP.
Up to 24 static secure MAC addresses per port.
Fanless design means fewer maintenance hassles.
DIN rail mounting kit included.
Hot swap extender without powering down.
A switch configures the extender for local (CO) or remote (CP) use.