Fibre Channel Cables And Connectors - Compaq StorageWorks 4000 - RAID Array White Paper

Understanding Compaq StorageWorks RAID Array 4000 and Infrastructure Cabling
A label describes the GBIC and distinguishes it as shortwave or long wave. The description may
spell out a GBIC's characteristics or it may use the Fibre Channel Standard convention for
labeling. The labeling convention is SPEED-MEDIA-TRANSMITTER-DISTANCE.
An example of a GBIC label is 100-M5-SN-I. Use Table 2 to decode the example label as
follows:
100 means a bandwidth of 100 MB/s.
M5 means 50-micron multi-mode cable.
SN means shortwave laser without OFC.
I means intermediate distance.
Table 2. Fibre Channel Standard convention for GBIC labeling
Speed
Media
Transmitter
Distance
* 1063 MBd is the data rate measured in megabaud and is equivalent to 106.3 MB/s, or 100 MB/s nominally.
** A cable labeled M6 can be used with an M5 GBIC.
*** Compaq only supports shortwave lasers without open fiber control (OFC), the SN version. OFC limits the amount
of light transmitted when the fiber connection is broken to prevent eye injury. Improvements in laser control
technology have eliminated the need for OFC.

Fibre Channel Cables and Connectors

Typically, fibre channel cables are a pair of fibers with connectors on each end. The fibers in a
fibre channel cable cross so that the input at one end of the fibre channel cable becomes the
output at the other end. The connectors are keyed to ensure that the connections are properly
oriented.
Compaq supplies 50-micron, multi-mode fibre channel cables in fixed lengths of 2 meters,
5 meters, 15 meters, 30 meters, and 50 meters. Compaq RA4000 storage system components ship
standard with 50-micron, multi-mode fibre channel cables. Support for 62.5-micron, multi-mode
and 9-micron, single-mode fibre channel cables is also available.
Fibre channel cables that connect to infrastructure cabling must match the fiber type of the
infrastructure cabling. For example, if 62.5-micron, multi-mode infrastructure cabling connects to
a wall outlet, the cabling that runs from the server to that wall outlet must be 62.5-micron,
multi-mode cable.
Connecting 50-micron fibre channel cable to 62.5-micron fibre channel cable can cause severe
degradation of the optical signal. This can result in marginal operation or an unreliable
connection.
Cable assembly suppliers can provide custom combinations of cable length, connector type, and
fiber type to mate with infrastructure cabling. See Acknowledgments and References later in this
document for suppliers.
ECG02030699A
100 = 100 MB/s*
SM = 9-micron single-mode
LL = long wave laser
(1300 nanometers)
L = long distance (2 m to 10 km)
200 = 200 MB/s
M5 = 50-micron multi-mode
SL = shortwave laser with OFC
(850 nanometers)
I = Intermediate distance (2 m to
500 m)
400 = 400 MB/s
M6** = 62.5-micron multi-mode
SN = shortwave laser without
OFC (850 nanometers)
S = short distance (2 m to
300 m)
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