1.2 What is Fibre Channel?

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 could include supercomputers, mainframes, workstations, and desktops, (personal computers).

Peripherals could 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. The following table demonstrates the various speeds that can be attained using the different cable types.

Type/Speed (Mhz)	Single Mode @9 um	Multi-mode @50 um	Multi-mode @62.5 um	Co-ax	Mini-Co-ax	Twinax	STP
133				100 m	42 m	93 m	80 m
266	1300nm @10 km	780nm @2 km	780nm @1 km	100 m	28 m	66 m	57 m
533	1300nm @10 km	780nm @1 km	780nm @1 km	71 m	19 m	46 m	46 m
1063	1300nm @10 km	780nm @500 m	780nm @175 m	50 m	14 m	33 m	28 m
2125	1300nm @2 km	780nm @500 m
4250	1300nm @2 km	780nm @175 m

1.2.1 Fibre Channel for Networking

Fibre Channel can be used for networking. The Fibre Channel standard was written to also cover networking protocols (system-to-system communication). Hewlett-Packard's networking implementation uses a speed of 25 Megabytes per second, (M/bytes/s, also known as Mbps) or 266 (265.625) megabaud. This is also known as quarter speed, with full speed being 100 Mbytes/s or 1063 (1062.5) megabaud. Full speed is also known as gigabit speed. Consult the publications listed in Section 6.2 for more information on Fibre Channel as applied to the networking environment.