1
Fibre Channel Overview
Fibre Channel is designed to carry various command sets and their
associated architectures over the same physical interface. Fibre Channel is
primarily a transport medium; therefore, it is independent of the function
for which it is used.
The TruCluster Software Products use the Fibre Channel Protocol (FCP) for
SCSI-3 to use Fibre Channel as the physical interface.
Fibre Channel, with its serial transmission method, overcomes the
limitations of parallel SCSI by providing:
•
Data rates of 100 MB/sec, 200 MB/sec, and 400 MB/sec
•
Support for multiple protocols
•
Better scalability
•
Improved reliability, serviceability, and availability
Fibre Channel uses an extremely high transmit clock frequency to achieve
the high data rate. Using optical fibre transmission lines allows the
high-frequency information to be sent up to 70 km, which is the maximum
distance between transmitter and receiver. Copper transmission lines
may be used for shorter distances. (Tru64 UNIX does not support copper
transmission lines.)
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Note
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The TruCluster Software Products support 500 meters between
the KGPSA and the switch or hub, and 500 meters between the
switch or hub and the HSG80 array controller. See Figure 1–4 for
an example cluster configuration.
1.1 Basic Fibre Channel Terminology
This section describes the basic Fibre Channel terminology:
AL_PA
The Arbitrated Loop Physical Address (AL_PA) is
used to address nodes on the Fibre Channel loop.
When a node is ready to transmit data, it transmits
Fibre Channel Overview 1–1
