passive hub

基本解释

The device can also be used as a standalone four-channel passive UTP receiver hub with integral distributed camera power outputs rated at one amp each.
同时，模块也可以作为一个单独的“四频道的被动UTP接收器”，与各分布的摄像头电源输出集成使用。
www.21csp.com.cn
The Terracotta "hub" prior to v2.3 was itself clusterable for fault-tolerance using an active/passive solution using shared disk (such as clustered NFS or SAN), which can be expensive.
在2.3版之前Terracotta的Hub使用共享硬盘（一个群集的NFS或者SAN）来实现活动/备用的群集故障容错方案，这样做的代价是高昂的。