HP 316095-B21 - StorageWorks Edge Switch 2/24 User manual

Glossary
hp StorageWorks
Directors and Edge Switches
Second Edition (July 2004)
Part Number: AA–RU5JB–TE/623–000005–001
This glossary defines terms used in manuals that support HP StorageWorks Directors and
Edge Switches.

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Printed in the U.S.A
Directors and Edge Switches Glossary
Second Edition (July 2004)
Part Number: AA–RU5JB–TE/623–000005–001

3Directors and Edge Switches Glossary
Glossary
Glossary
Glossary
This glossary defines terms used in manuals that support the following HP
StorageWorks storage area network (SAN) products:
■Director 2/64
■Director 2/140
■Edge Switch 2/12
■Edge Switch 2/16
■Edge Switch 2/24
■Edge Switch 2/32
The glossary includes terms that relate specifically to the supported products. It
does not include many terms that are generally well-known in the SAN industry.
10BaseT
An implementation of the IEEE Ethernet standard for 24-gauge unshielded twisted-pair wiring,
using a baseband transmission rate of ten Mbps.
100BaseT
An implementation of the IEEE Ethernet standard for 24-gauge unshielded twisted-pair wiring,
using a baseband transmission rate of 100 Mbps.
access control
Method of control (with associated permissions) by which a set of devices can access other
devices across a network. See also persistent binding and zoning.
active configuration
In S/390 mode, the director or switch configuration that is determined by the status of the
connectivity attributes.
active FBML
The active fabric binding membership list. When fabric binding is active, the list of fabric
members with which the product is allowed to communicate. See fabric binding and fabric
binding membership list.

Glossary
4 Directors and Edge Switches Glossary
active FRU
A redundant field-replaceable unit that is currently operating as the active and not the backup
FRU. See also backup FRU.
active port address matrix
In S/390 mode, an active port address matrix is the port address matrix that is currently active or
operational on an attached director or switch. See also connectivity capability.
active zone set
Single zone set that is active in a multiswitch fabric. It is created when you enable a specified
zone set. This zone set is compiled by checking for undefined zones or aliases.
address name
See port name.
agent
Software that processes queries on behalf of an application and returns replies.
alarm
Simple network management protocol (SNMP) message notifying an operator of a network or
device problem.
allowed connection
In S/390 mode in a director or switch, the attribute that, when set, establishes dynamic
connectivity capability. See also blocked connection, connectivity attribute, dynamic
connectivity.
alias server
Fabric software facility that supports multicast group management.
allowed port connection
In S/390 mode, this attribute establishes dynamic connectivity capability.
American National Standard Code for Information Interchange
ASCII. A standard character set consisting of 7-bit coded characters (8-bit including parity
check) used for information exchange between systems and equipment.
American National Standards Institute
ANSI. A national organization consisting of producers, consumers, and general interest groups
that establishes procedures by which accredited organizations create and maintain industry
standards in the United States
application program interface
API. A set of programming functions and routines that provides access between protocol layers,
such as between an application and network services.

Glossary
5Directors and Edge Switches Glossary
application-specific integrated circuit
ASIC. An asynchronous transfer mode (ATM) local area network/ wide area network
(LAN/WAN) circuit using cell relay transport technology. ASICs are designed for a specific
application or purpose, such as implementing the lower-layer Fibre Channel protocol (FC-0).
They are particularly suited to sending video and audio information, as well as text. ASICs
differ from general-purpose devices such as memory chips or microprocessors.
area
The second byte of the node port (N_Port) identifier.
arbitrated loop
One of the three connection topologies offered by Fibre Channel protocol. Up to 126 node ports
and one fabric port can communicate without the need for a separate switched fabric.
arbitrated loop physical address
(AL_PA) — A 1-byte value used in the arbitrated loop topology that identifies loop ports
(L_Ports). This value then becomes the last byte of the address identified for each public L_Port
on the loop.
arbitration
Process of choosing one device from a collection of devices that request service simultaneously.
attribute
In S/390 mode, the connection status of the address on a configuration matrix: allowed,
blocked, or prohibited.
audit log
Log summarizing actions (audit trail) made by the user.
authentication
Verification of identity for a person or process.
backbone
Cable on which two or more stations or networks may be attached, typically used to link
computer networks at one site with those at another. Smaller branch networks are sometimes
called ribs.
backplane
The backplane provides 48 VDC power distribution and connections for all logic cards.
backup FRU
When an active field-replaceable unit (FRU) fails, an identical backup FRU takes over
operation automatically (failover) to maintain director and Fibre Channel link operation. See
also active FRU.
bandwidth
(1) The difference (expressed in Hertz) between the highest and lowest frequencies in a range of
frequencies. (2) The data transfer rate of a network or electronic communication system.

Glossary
6 Directors and Edge Switches Glossary
BB_Credit
See buffer-to-buffer credit.
beaconing
Use of light-emitting diodes on ports, port cards, field-replaceable units, and directors to aid in
the fault-isolation process. When enabled, active beaconing causes LEDs to flash for selected
components.
BER
See bit error rate.
bezel
A removable panel that covers empty drive bays and port cards.
bidirectional
In Fibre Channel, the capability to simultaneously communicate at maximum speeds
(100 Mbps) in both directions over a link.
bit error rate
(BER) — Ratio of received bits that contain errors to total of all bits transmitted.
blocked connection
In S/390 mode, in a director or switch, the attribute that, when set, removes the communication
capability of a specific port. A blocked address is disabled so that no other address can be
connected to it. A blocked attribute supersedes a dedicated or prohibited attribute on the same
address. See also allowed connection, connectivity attribute, dynamic connection, and dynamic
connectivity.
blocked port
Devices communicating with the port are prevented from logging into the director or
communicating with other devices attached to the director. A blocked port continuously
transmits the offline sequence.
B_Port
See bridge port.
bridge
Device that connects and passes packets between two network segments that use the same
communications protocol.
bridge port
(B_Port) — (1) In Fibre Channel protocol, a fabric inter-element port used to connect bridge
devices with E_Ports on a switch. B_Ports provide a subset of E_Port functionality. (2) A term
for a physical interface between the fabric (switch) and a bridge device. The interface is
identical to an expansion port (E_Port), but it does not participate in full expansion port
protocols. As such, it does not assign domain IDs or participate in routing protocol. See also
expansion port, fabric port, generic port, node port, and segmented E_Port.

Glossary
7Directors and Edge Switches Glossary
broadcast
Send a transmission to all node ports (N_Ports) on a fabric. See also broadcast frame and
multicast.
broadcast frame
Data packet, also known as a broadcast packet, whose destination address specifies all
computers on a network. See also broadcast and multicast.
buffer
Storage area for data in transit. Buffers compensate for differences in processing speeds
between devices. See also buffer-to-buffer credit
buffer-to-buffer credit
(BB_Credit) — The maximum number of frames a port can transmit without receiving a receive
ready signal from the receiving device.
bypassed port
If a port is bypassed, all serial channel signals route past the port. A device attached to the port
cannot communicate with other devices in the loop.
cascade
Linking two or more Fibre Channel switches to form a larger switch or fabric. The switched
link through fiber cables attached between one or more expansion ports (E_Ports). See also
expansion port.
call-home
Product feature that requires installation of HP Proactive Service software and enables the
HAFM server to automatically transmit system events (failure information) to aN HP customer
support center. The HP support center server accepts calls from the HAFM server, logs reported
events, and can notify one or more support center representatives.
cell
In S/390 mode, in a port address matrix, a cell is the intersection point between a horizontal port
address and a vertical port address. A selected cell is indicated by the cell cursor.
chained
Two directors or switches that are physically attached.
channel
Point-to-point link that transports data from one point to the other.
channel-attached
(1) Pertaining to direct attachment of devices by data I/O channels to a computer. (2) Pertaining
to devices attached to a control unit by cables, not telecommunication lines.
channel path
A single interface between a central processor and one or more control units along which
signals and data can be sent to perform I/O requests.

Glossary
8 Directors and Edge Switches Glossary
channel path identifier
(CHPID) — In a channel subsystem, a value assigned to each installed channel path of the
system that uniquely identifies that path to the system.
channel-to-channel
CTC. A channel attached to another channel (channel-to-channel) and specifies the I/O mode of
operation for the channel path under the I/O configuration program (IOCP) channel path
identifier (CHPID) statement ‘Type’ parameter. See also channel path identifier.
channel wrap test
A diagnostic procedure that checks S/390 host-to-director connectivity by returning the output
of the host as input. The test is host-initiated, and transmits Fibre Channel frames to a director
port. A director port enabled for channel wrapping echoes the frame back to the host.
CHPID
See channel path identifier.
Class 2 Fibre Channel service
Provides a connectionless (not dedicated) service with notification of delivery or nondelivery
between two N_Ports. In-order delivery of frames is not guaranteed.
Class 3 Fibre Channel service
Provides a connectionless (not dedicated) service without notification of delivery or
nondelivery between two N_Ports. Also known as datagram.
Class F Fibre Channel service
Used by switches to communicate across interswitch links (ISLs) to configure, control, and
coordinate a multiswitch fabric.
class of Fibre Channel service
Defines the level of connection dedication, acknowledgment, and other characteristics of a
connection. Class 2, Class 3, and Class F services are supported.
client/server computing
Architectural model that functionally divides that execution of a unit of work between activities
initiated by an end user or program (client) and those maintaining data (servers). Originally
thought to make mainframes obsolete.
cluster
A group of processors interconnected by a high-speed network (typically dedicated) for
increased reliability and scalability. Clusters are groupings of multiple servers in which
information is shared among systems. When a server in a cluster fails, one of the other servers
in the cluster assumes the responsibility of the failed server, thereby ensuring server,
application, and data availability.

Glossary
9Directors and Edge Switches Glossary
community name (SNMP)
A name that represents a simple network management protocol (SNMP) community that the
agent software recognizes as a valid source for SNMP requests. A product recognizes a
management station as a valid recipient for trap information when the station’s community
names are configured.
community profile
Information that specifies which management objects are available to what management
domain or SNMP community name.
concurrent firmware upgrade
Firmware is upgraded without disrupting switch operation.
concurrent maintenance
Ability to perform maintenance tasks, such as removal or replacement of field-replaceable units
(FRUs), while normal operations continue without interruption. See also nondisruptive
maintenance.
configuration data
Configuration data includes identification data, port configuration data, operating parameters,
SNMP configuration, and zoning configuration. A configuration backup file is required to
restore configuration data if the control processor (CTP) card in a nonredundant director is
removed and replaced.
connectionless
Nondedicated link. Typically used to describe a link between nodes that allows the switch to
forward Class 2 or Class 3 frames as resources (ports) allow. Contrast this type of link to the
dedicated bandwidth that is required in a Class 1 Fibre Channel Service point-to-point link.
connectivity attribute
In S/390 mode, the characteristic that determines port address status for the director or switch.
See also allowed connection, blocked connection, connectivity capability, connectivity control,
dynamic connection, dynamic connectivity, and unblocked connection.
connectivity capability
(1) The capability that allows attachment of a device to a system without requiring physical
reconfiguration of either the device or the interconnections. (2) The director or switch capability
that allows logical manipulation of link connections to provide physical device attachment. See
also active port address matrix, connectivity attribute, and connectivity control.
connectivity control
In S/390 mode, in a director or switch, the method used to change port address connectivity
attributes and determine the communication capability of the link attached to the port. See also
active port address matrix, connectivity attribute, and connectivity control.

Glossary
10 Directors and Edge Switches Glossary
connector
See optical fiber connector.
control processor card
(CTP card) — Circuit card that contains the director microprocessor. The CTP card also
initializes hardware components of the system after power-on. A 10 Mbps RJ-45 twisted pair
connector is located on the CTP card to connect to an Ethernet LAN and communicate with the
HAFM server or a specific management station.
control unit
A device that controls the reading, writing, or displaying of data at one or more input/output
units.
control unit port
An internal director port on the CTP card that communicates with the attached IBM S/390 or
similar processor channels to report error conditions and link initialization.
CRC
See cyclic redundancy check.
CTP card
See control processor card.
CUP
See control unit port.
cyclic redundancy check
(CRC) — System of error checking performed at both the sending and receiving station using
the value of a particular character generated by a cyclic algorithm. When the values generated at
each station are identical, data integrity is confirmed.
DASD
Direct access storage device, such as a disk drive.
datagram
See Class 3 Fibre Channel service.
data directory
Directory that contains critical information for all managed products (including directors and
switches). Information stored here includes:
■All configuration data
■All log files
■Call-home settings
■Firmware library
■Zoning library