Fibre Channel (FC) is a
specification of high-speed connections of electronic devices, which allows you
to create a flexible configuration. FC has the properties of network
technology, such as Ethernet, and tires, such as SCSI. It can be used in a
network for connecting multiple systems and reservoirs. Any system can access
any storage device. This means that the amount of data available within the
enterprise as a whole increases. Speed high:
today Fibre Channel is capable of transmitting large amounts of data at a speed
of 100 MB / s (full duplex - 200 MB / s). Specifications Fibre Channel protocol includes five levels, of which the
first three are physical levels. Specifications these three levels approved as
standard. Specifications levels 4 and 5 (FC3 and FC4) developed. Nevertheless
allowed some freedom of interpretation, which is used by manufacturers to
create specific functions of its own products and gain an advantage over
competitors. This behavior leads manufacturers, in particular, to the fact that
a single standard for the administration of FC-based infrastructure has not yet
appeared. Fibre Channel can be used in five different classes of service and is
being implemented in three topologies. • Class 1: Acknowledged Connection
Service for large files and full bandwidth capacity; • Class 2: Acknowledged
Connection Service for clusters, networks and OLTP; • Class 3: Unacknowledged
Connection Service for storage, networking, broadband; • Class 4: Fractional
Bandwith Service for real-time audio / video; • Class 5: Service for unicast
video broadcast (one to many). To connect the storage subsystems and robotic
tape libraries used Class 3, for synchronous replication of data in clusters
applicable class 2. In a circuit topology implemented "point to
point" , ring topology FC-AL (Fibre Channel Arbitrated Loop) and Switched
Fabric. Topology "point-to-point» Fibre Channel provides the easiest way
to connect the two nodes. This delivers full bandwidth of 100 MB / s, but the
scalability is limited. FC-AL is a ring topology like Token Ring and FDDI. It
brings together up to 126 nodes in a single ring, and allows you to share 100
MB / s bandwidth. In addition, it provides good scalability of the system. Topology
Switched Fabric permits the consolidation of 16 million units, and forms the
basis for connecting the other rings and knots.
Posted By: Wasim Javed
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