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HP N1200-320 User Manual

Page 127

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N1200-320 4Gb Network Storage Router user and service guide 127

SCSI bus

The means of transferring SCSI data between SCSI devices. It is an 8-bit or 16-bit bus that

supports up to eight or sixteen devices (including itself), in any mix of initiators and targets, with

the limitation that at least one initiator and one target must be present.

SCSI device

A single unit on the SCSI bus, identifiable by a unique SCSI address. A SCSI device can act as

an initiator or target. For SCSI-3, each SCSI device supports up to sixteen LUNs.

SCSI port

An opening at the back of the network storage router providing connection between the SCSI

adapter and the SCSI bus.

SCSI status

A menu name used to show the number of SCSI devices on the bus.

small formfactor

pluggable (SFP)

A physical component that manages the functions of the FC-0 layer, which is the physical

characteristic of the media and interface, including drivers, transceivers, connectors, and

cables. Mounts on a FC adapter card and connects the network storage router to a FC host.

shortwave

Lasers or LEDs that emit light with wavelengths around 780 nm or 850 nm. When using

multimode fibre (50 nm), shortwave lasers can be used with FC links less than 500m. To

achieve longer lengths, single-mode fibre is required. The preferred fibre core size is 50 micron

as this fibre has large bandwidth so that the distance is limited by the fibre attenuation. A

62.5 micron core size is also supported for compatibility with existing FDDI installations. Fibre

of this type has smaller bandwidth and, in this case, the distance is limited by the fibre

bandwidth.

speed

A status type in the FC Status Menu showing the speed (1063 Mbps) of the FC adapter.

switched fabric

A FC term describing a switched topology, which is one of the three existing FC topologies.

Fabric elements interconnect various N_Ports or NL_Ports and are responsible for frame routing.

TCP

Transmission Control Protocol

target

A device (usually a peripheral) that responds to an operation requested by an initiator (usually

a host system). Peripherals are targets, but for some commands (for example, a SCSI COPY

command), the peripheral may need to act temporarily as an initiator.

terminator

block/termination

An electrical connection at each end of the SCSI bus composed of a set of resistors (or possibly

other components). Its function is to provide a pull-up for open collector drivers on the bus, and

also impedance matching to prevent signal reflections at the ends of the cable.

The SCSI bus requires termination at both ends of the bus. One end of the SCSI bus is

terminated by the SCSI adapter’s internal termination. The other end should have a terminator

placed on the SCSI connector on the last SCSI peripheral. If this device is not terminated, data

errors may occur.

topology

The physical or logical layout of nodes on a network. FC topologies include Point-to-Point,

FC-AL, and Fabric.

view node name

A status type in the FC Status Menu showing the identification of the node.

view port name

A status type in the FC Status Menu showing the identification of the port.

world wide name

(WWN)

A Name_Identifier which is worldwide unique, and represented by a 64-bit unsigned binary

value.