How to get to grips with fibre channel

Fibre Channel is a one Gbit-per-second data transfer interface technology. Over the past year, more than 70 disk drive, disk array, server and networking connectivity suppliers have nailed their colours to the fibre channel mast because of its high bandwidth, high scalability, and its ability to support multiple protocols, such as SCSI and IP, over a single connection.

Fibre channel, or fibre channel arbitrated loop (FC-AL), was originally sold by its inventor, Hewlett-Packard, and by Digital. It is an open standard and operates over copper and fibre optic cabling at distances of up to 10km.

The technology first appeared in enterprise networking applications and point-to-point Raid and mass storage subsystems. It is rapidly expanding to include OLTP servers, and video and graphics networks such as pre-press, video editing, and visual imaging systems.

It conforms to the SCSI-3 standard, a more flexible solution than today?s SCSI-2, so you can mix and match devices from different vendors on the same network. The backbone system works four times as fast. Fibre channel increases the distance between the server and the storage, so you can attach more servers in one continuous loop to boost performance and capacity and improve scalability. You can also patch network storage devices all over the place, without having to associate them to a single host.

There are moves afoot to converge fibre channel and its rival SSA (serial storage architecture ), sold by its creator IBM and Xyratex, into one standard. But at the moment they are sold by two separate camps of vendors. Now that Sun, Unisys and other server vendors have come out in support of fibre channel, expect a wave of publicity to hit our shores in 1998.

?Microsoft?s commitment to fibre channel in NT 5.0 will be the building block for increased functionality in future NT releases,? such as the support of Microsoft?s Wolfpack cluster software solution,? says Jay Kramer, director of business development and marketing for Unisys? storage systems programme.

Performance might seem to be the main reason for preferring fibre channel. Its 100Mbits- per-second bandwidth gets a lot of attention, but its architectural considerations are even more significant. It has 100Mbits per second available per port, for a total of 200Mbits per seconds of bandwidth that can be used in either direction.

This is enough for any video or imaging application, and you don?t need an expensive disk controller. Fibre channel therefore allows the workstation manufacturer to offer one hardware platform with the right performance characteristics for a number of applications.

When you buy a system which accommodates fibre channel, you don?t have to worry if you have sufficient performance if you later want to add a video application. If you were using SSA as the disk interface, you?d probably need an additional controller.

There are a number of companies developing fibre channel products and Cern maintains a page about fibre channel products on the Web at www1.cern/his/fcs/manufac/ manufac.htm.

Two industry associations have formed around the fibre channel technology: the Fibre Channel Association (FCA) and the Fibre Channel Loop Community (FCLC), which maintains an updated vendor contact list on its site at www. fcloop.org.

The FCA works to promote awareness of fibre channel technologies. Write to 12407 MoPac Expressway North 100-357 PO Box 9700 Austin, Texas, or visit www. amdahl.com/ext/CARP/FCA/

The FCLC was formed to encourage the broad use of FC-AL for storage and networking applications. It functions as an active fibre channel educational and marketing organisation, and attends several shows a year. Write to Michael E. Fitzpatrick, chairman, PO Box 2161 Saratoga, California 95070, or email mfitzpatrick@fcpa.fujitsu.com