HP StorageWorks 4000 Understanding Compaq StorageWorks RAID Array 4000 and Inf - Page 7

Understanding Compaq StorageWorks RAID Array 4000 and Infrastructure Cabling 7 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 100 = 100 MB/s* 200 = 200 MB/s 400 = 400 MB/s Media SM = 9-micron single-mode M5 = 50-micron multi-mode M6** = 62.5-micron multi-mode Transmitter LL = long wave laser (1300 nanometers) SL = shortwave laser with OFC SN = shortwave laser without (850 nanometers) OFC (850 nanometers) Distance L = long distance (2 m to 10 km) I = Intermediate distance (2 m to S = short distance (2 m to 500 m) 300 m) * 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