3.2 How Does Fibre Channel Help?

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Fibre Channel is a new communications protocol designed to overcome the limitations of existing architectures. It is a generic data transport mechanism with the primary task of transporting data at the fastest rate possible using current technology. Fibre Channel is a scalable interface for achieving high-speed data transfer rates among heterogeneous systems and peripherals. System types include supercomputers, mainframes, workstations, and desktop PCs.

Peripherals include mass storage devices such as disk arrays and possibly tape libraries. The main purpose of Fibre Channel is to have any number of existing protocols over a variety of physical media and existing cable options.

Table 3-1 shows the various speeds and distances that can be attained using different cable types.

Table 3-1. Cable Types, Speeds, and Distances

SPEED (Mbps)	9 µm Single Mode	50 µm Multimode	62.5 µm Multimode	COAX	Mini COAX	TWINAX	STP
133				100 m	42 m	93 m	80 m
266	10 km	2 km	1 km	100 m	28 m	66 m	57 m
533	10 km	1 km	1km	71 m	19 m	46 m	48 m
1063	10 km	500 m	175 m	50 m	14 m	33 m	28 m
2125	2 km	500 m
4250	2 km	175 m

3.2.1 Fibre Channel Use for Mass Storage

Since Fibre Channel is a generic data transport mechanism, it can transmit a number of existing networking and I/O protocols:

I/O protocols:

SCSI
HIPPI
IPI

Network protocols:

IP
IEEE 802.2

Hewlett-Packard has chosen to support the SCSI-3 protocol over Fibre Channel for its mass storage environment. Mass storage consists of several device classes:

tapes
disks
disk arrays

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