仲裁环路（arbitrated loop），如果算上连接到一个光钎连接控的端口它支配 127 个设备。仅仅一个连接可能是一个连接孔。设备在一个单行道环方式下被连接 也叫做 FC-A L 一个不需要
光纤通道转换器光纤通道拓扑。
A private arbitrated loop is a configuration where up to 126 devices can be attached. The attachment point called NLport
(loop ports). FC-AL is a low cost connectivity solution because it does not require expensive switching devices.
Instead low cost hubs are used to increase server and storage connectivity. Hubs have won wide acceptance in JBOD
(Just a Bunch of Disks) environments, because just as JBOD costs less than enterprise storage, hubs cost less than
switched fabric.