Arbitrated Loop

Arbitrated loop, also known as FC-AL, is a Fibre Channel topology in which devices are connected in a one-way loop fashion in a ring topology. Historically it was a lower-cost alternative to a  fabric topology. It allowed connection of many servers and computer storage devices without using then very costly Fibre Channel switches. As of 2007 the cost of the switches dropped considerably, so FC-AL is rarely used for a server-to-storage communication. It is however still commonly utilized on backend of some disk array controllers.
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