Storage Area Networking Glossary

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

ABTS Abort Basic Link Service.
ACC Accept link service reply; the normal reply to an Extended Link Service request (such as FLOGI), indicating that the request has been completed.
Access fairness A process by which contending nodes are guaranteed access to an Arbitrated Loop.
Access method The method used to access a physical medium in order to transmit data.
ACK Acknowledgement frame; used for end-to-end flow control; verifies receipt of one or more frames from Class-1 or Class-2 services.
Active copper A fibre channel connection that allows copper cabling up to 33 meters (100 yards) in length between devices.
Address identifier A 24-bit number used to indicate the link-level address of communicating devices. In a frame header, the address identifier indicates the source ID (S_ID) and the destination ID (D_ID) of the frame respectively.
Alias server A proposed standard as part of FC-PH-3; it will use the well-known address FFFFF8 and will maintain identifier mappings to support multicast group management.
AL_PA Arbitrated Loop Physical Address; an 8-bit value used to identify a device participating in an Arbitrated Loop.
AL_TIME Arbitrated Loop Timeout value; twice the amount of time it would take for a transmission word to propagate around a worst-case loop. The default value is 15 milliseconds (ms).
ANSI American National Standards Institute; the governing body for standards in the U.S.
ARB Arbitrative Primitive Signal; this applies only to an Arbitrated Loop topology, and is transmitted as the fill word by an L_Port to indicate the port is arbitrating access to the loop.
Arbitrated Loop A shared 100-megabytes-per-second fibre channel transport supporting up to a maximum of 126 devices and 1 attachment to a fabric. Ports with lower AL_PAs have higher priorities.
Arbitration A method of gaining orderly access to a shared-loop topology.
ARP Address Resolution Protocol; a TCP/IP function for translating an IP address to an Ethernet (link-level MAC address).
ASIC Application-Specific Integrated Circuit.
ATM Asynchronous Transfer Mode; a high-speed packet-switching transport used for transmitting data over LANs or WANs that transmits fixed-length units of data. It provides any-to-any connectivity and nodes can transmit simultaneously.
Bandwidth The transmission capacity of the cable, link, or system.
BB_Credit Buffer-to-buffer credit; used to determine how many frames can be sent to the recipient.
Broadcast Sending a transmission to all N_Ports on a fabric.
Bypass circuitry Circuits that automatically remove a device from the data path when valid signals are dropped.
CAM Content addressable memories.
Camp on Proposed as an optimization for fabric queue connect requests so that they are satisfied in the order received.
Cascade Connecting two or more fibre channel hubs or switches to increase port capacity or distance. Seven levels of cascading is the limit. SilkWorm 1000 switches can cascade up to 32; SilkWorm 2000 switches can cascade up to 239.
CDR Clock and data recovery circuitry.
CE Conformit?Europ?nne.
Channel A point-to-point link whose task is to transport data from one point to another.
CIM Common Information Model; a management structure enabling disparate resources to be managed by a common application.
Class 1 A connection-oriented class of service that requires acknowledgment of frame delivery.
Class 2 A connectionless class of service that requires acknowledgment of frame delivery between N_Ports.
Class 3 A connectionless class of service that requires no acknowledgment of frame delivery between N_Ports.
Class 4 A connection-oriented service that allows fractional parts of the bandwidth to be used in a virtual circuit.
Class 6 A connection-oriented multicast service geared toward video broadcasts between a central server and clients.
Class F A connectionless class of service that gives notification of delivery or non-delivery between E_Ports, used for control, coordination, and configuration of the Fabric.
CLS Close Primitive Signal; only in an Arbitrated Loop; sent by an L_Port that is currently communicating on the loop, to close communication to an other L_Port.
Community A relationship in SNMP between an SNMP agent and a set of SNMP managers that defines authentication, access control, and proxy characteristics.
Controller A computer module that interprets signals between a host and a peripheral device. The controller typically is part of the peripheral device.
COS Class of service.
CRC Cyclic Redundancy Check; a self-test for error detection and correction.
Credit A numeric value that represents the maximum number of receive buffers provided by an F/FL_Port to its attached N/NL_Port such that the N/NL_Port may transmit frames without overrunning the F/FL_Port.
Cut-through A switching technique that allows a routing decision to be made as soon as the destination address of the frame is received.
Datagram A Class 3 Fibre Channel service that allows data to be sent quickly to multiple devices attached to the fabric, with no confirmation of receipt.
Dedicated simplex A means that permits a single N_Port to simultaneously initiate a session with another N_Port as an initiator, and have a separate Class 1 connection to another N_Port as a recipient.
Disparity The relationship of 1s and 0s in an encoded character; positive disparity contains more 1s, negative disparity contains more 0s, neutral disparity contains an equal number of 1s and 0s.
DLS Dynamic Load Sharing; allows for recomputing of routes when an Fx or E_Port comes up or down.
Domain ID A unique number between 1 and 239 on a SilkWorm 2000 Series switch that identifies the switch to a fabric.
DWDM Dense Wave Digital Multiplexing; see WDM. Allows more wavelengths to use the same fiber.
E_D_TOV Error-Detect Time Out Value; the maximum round-trip time that an operation could require before declaring an error condition.
EE_Credit End-to-end credit; used to manage the exchange of frames by two communicating devices and set the maximum number of frames that may remain unacknowledged.
EIA Electronic Industries Association.
8b/10b encoding An encoding scheme that converts an 8-bit byte into two possible 10-bit characters; used for balancing 1s and 0s in high-speed transports.
ELP Extended Link Process.
Emulex A brand of host bus adapter.
EOF End Of Frame; a group of ordered sets used to mark the end of a frame.
E_Port An expansion port connecting two switches to make a fabric.
Exchange The highest-level fibre channel mechanism used for communication between N_Ports. They are composed of 1+ related sequences and work either uni- or bi-directionally.
Fabric One or more fibre channel switches in some networked topologies. One of three fibre channel topologies, when N_Ports are connected to F_Ports on a switch.
FAN Fabric Address Notification; keeps the AL_PA and fabric address when loop re-initializes if the switch supports FAN.
F_BSY Fabric Port Busy Frame; a frame issued by the fabric to indicate that a frame cannot be delivered because the fabric or destination N_Port is busy.
FCA Fibre Channel Association.
FC-0 Lowest layer on fibre channel transport; represents the physical media.
FC-1 This layer contains the 8b/10b encoding scheme.
FC-2 This layer handles framing and protocol, frame format, sequence/exchange management, and ordered set usage.
FC-3 This layer contains common services used by multiple N_Ports in a node.
FC-4 This layer handles standards and profiles for mapping upper-level protocols such as SCSI and IP onto the Fibre Channel Protocol.
FC-AL Fibre Channel Arbitrated Loop.
FC-AV Fibre Channel Audio Visual.
FC-CT Fibre Channel Common Transport.
FC-FG Fibre Channel Generic requirements.
FC-FLA Fibre Channel Fabric Loop Attachment.
FC-GS Fibre Channel generic services.
FC-GS-2 Fibre Channel second-generation generic services.
FC_IP Fibre channel over IP protocol.
FC-PH The fibre channel physical and signaling standard for FC-0, FC-1, and FC-2 layers of the Fibre Channel Protocol, and also indicates signaling used for cable plants, media types, and transmission speeds.
FC-PH-2 Second-generation physical interface.
FC-PH-3 Third-generation physical interface.
F_RJT Fabric Port Reject Frame; a frame issued by the fabric to indicate that delivery of a frame is being denied, maybe because class is not supported, or there is an invalid header, or no N_Port is available.
FC_SB Fibre Channel Single Bytes.
FC-SW Fibre Channel Switch Fabric; specifies tools and algorithms for interconnection and initialization of fibre channel switches to create a multiswitch fibre channel fabric.
FC-SW-2 Fibre Channel Switch Fabric (second generation); specifies tools and algorithms for interconnection and initialization of fibre channel switches to create a multiswitch fibre channel fabric.
FC_VI Fibre Channel Virtual Interface.
FCC Federal Communications Commission.
FCIA Fibre Channel Industry Association; its mission is to nurture and help develop the broadest market for fibre channel products.
FCLC Fibre Channel Loop Community.
FCP Fibre Channel Protocol; SCSI to fibre channel mapping.
FDDI Fibre Distributed Data Interface; ANSI architecture for a Metropolitan Area Network (MAN); a network based on the use of optical-fibre cable to transmit data at 100 megabits per second.
FFFFF5 Well-known fibre channel address for a Class 6 multicast server.
FFFFF6 Well-known fibre channel address for a clock synchronization server.
FFFFF7 Well-known fibre channel address for a security key distribution server.
FFFFF8 Well-known fibre channel address for an alias server.
FFFFF9 Well-known fibre channel address for a QoS facilitator.
FFFFFA Well-known fibre channel address for a management server.
FFFFFB Well-known fibre channel address for a time server.
FFFFFC Well-known fibre channel address for a directory server.
FFFFFD Well-known fibre channel address for a fabric controller.
FFFFFE Well-known fibre channel address for a fabric F_Port.
FFFFFF Well-known address for a broadcast alias-ID.
Fill word The primitive signal used by L_Ports to be transmitted between frames.
FL_Port A fabric loop port to which a loop attaches; needs FL card LED turned on. It is the gateway to the fabric for NL_Ports on a loop.
Flash Programmable NVRAM memory that maintains its contents.
FLOGI Fabric Login; a process by which a node makes a logical connection to a fabric switch. F_Port A fabric port to which an N_Port attaches.
Fractional Bandwidth The partial use of a link to send data back and forth, with a maximum of 254 Class 4 connections per N_Port.
Frame A data unit containing a start-of-frame (SOF) delimiter, header, payload, cyclic redundancy check (CRC), and an end-of-frame (EOF) delimiter. The payload can be 0-2112 bytes, and the CRC is 4 bytes.
FRU Field Replaceable Unit; a component that can be swapped out upon failure.
FSP Fibre Channel Service Protocol; The common FC-4 level protocol for all services, transparent to the fabric type or topology.
FSPF Fibre Shortest Path First; a routing protocol used by fibre channel switches.
Full duplex Concurrent transmission and reception of data on a link.
Full fabric citizenship A loop device that has an entry in name server.
Gateway Hardware that connects incompatible networks by providing the necessary translation, both for hardware and software.
GBIC Gigabit Interface Converter; a removable transceiver module permitting fibre channel and Gigabit Ethernet physical-layer transport.
Gbps Gigabits per second.
GBps Gigabytes per second.
Gigabit 1,062,500,000 bits per second in fibre channel.
GLM Gigabit Link Module; a semitransparent transceiver that incorporates serializing/deserializing functions.
G_Port A generic port that supports either E_Port or F_Port functionality.
GUI Graphical User Interface.
HBA Host Bus Adapter; an interface between a server or workstation bus and the fibre channel network.
HiPPI High-performance Parallel Interface; an 800Mbit/sec interface normally used in supercomputer environments.
Hot swappable A component that can be replaced while under power.
HSSDC High Speed Serial Data Connection; a form factor that allows quick connections for copper interfaces.
HTTP HyperText Transfer Protocol; the standard TCP/IP transfer protocol used on the World Wide Web.
Hub A fibre channel wiring concentrator that collapses a loop topology into a physical star topology. A hub automatically recognizes an active node and inserts it into the loop. A node that is not functioning is automatically removed from the loop.
Hunt Group A number of N_Ports registered as a single Alias_ID, so the fabric can route it to a port that is free.
Idle An ordered set transmitted continuously over a link when no data is being transmitted, to maintain an active link over fibre. It also helps maintain bit, byte, and word synchronization.
In-band Transmission of management protocol over the fibre channel transport.
Initiator A server or workstation on a fibre channel network that initiates transactions to tapes or disks.
Intercabinet A specification for copper cabling that allows up to 33-meter (100-yard) distances between cabinets.
Intermix Allows any unused bandwidth in a Class 1 connection to be used by Class 2 or Class 3.
Interswitch link See ISL.
Intracabinet A specification for copper cabling that allows up to a 13-meter (42-foot) distance within a single cabinet.
IOD In Order Delivery; a parameter than when set, guarantees that frames get delivered in order, or they are dropped.
IP Internet Protocol; the addressing part of TCP/IP.
IPI Intelligent Peripheral Interface.
ISL Interswitch Link; a connection between two switches using the E_Port.
Isolated E_Port This occurs when an ISL is online but not operational between switches because of overlapping domain IDs or no identical parameters such as E_D_TOVs.
ISP Internet Service Provider.
Jaycor A brand of host bus adapter. Now known as JNI.
JBOD Just a Bunch Of Disks; a term for disks typically configured as an Arbitrated Loop segment in a single chassis.
Jitter A deviation in timing for a bit stream as it flows through a physical medium.
K28.5 A special 10-bit character used to indicate the beginning of a fibre channel command.
LAN Local Area Network; a network where transmissions are typically under 5 kilometers (3.4 miles).
Latency The period of time that a frame is held by a network device before it is forwarded.
LED Light Emitting Diode; a status indicator on a switch, typically yellow or green.
Link control facility A termination card handling physical and logical control of the fibre channel link for each mode.
LIFA Loop Initialization Fabric Assigned frame; contains bitmap of all fabric assigned AL_PAs and is the first frame transmitted in the loop initialization process after a temporary loop master has been selected.
LIHA Loop Initialization Hard Assigned frame; a hard assigned AL_PA that is indicated by a bit set and is the third frame transmitted in the loop initialization process after a temporary loop master has been selected.
LILP Loop Initialization Loop Position frame; the final frame transmitted in a loop initialization process. A returned LIRP contains an accumulation of all of the AL_PA position maps. This allows all loop members to determine their relative loop position. This is an optional frame and is not transmitted unless the LIRP is also transmitted.
Link A bi-directional point-to-point serial data channel.
LIP Loop Initialization Process; a means to get an AL_PA address, to indicate a loop failure or to reset a node.
LIPA Loop Initialization Previously Assigned; where the device marks a bit in the bitmap if it had not logged in with the fabric in a previous loop initialization.
LIRP Loop Initialization Report Position frame; the first frame transmitted in the loop initialization process after all L_Ports have selected an AL_PA. It gets transmitted around the loop so all L_Ports can report their relative physical position. This is an optional frame.
LISA Loop Initialization Soft Assigned frame; the fourth frame transmitted in the loop initialization process after a temporary loop master has been selected. L_Ports that have not selected an AL_PA in a LIFA, LIPA, or LIHA frame will select their AL_PA here.
LISM Loop Initialization Select Master frame; the first frame transmitted in the initialization process when L_Ports select an AL_PA. It is used to select a temporary loop master or the L_Port that will subsequently start transmission of the LIFA, LIPA, LIHA, LISA, LIRP, or LILP frames.
Login server The unit that responds to login requests.
Loom The code name given to the second-generation Brocade fabric ASIC. This is the ASIC that is used in the SilkWorm 2xxx series of switches.
Looplet Private Arbitrated Loops connected by a fabric.
LPB Loop Port Bypass; a primitive sequence transmitted by an L_Port to bypass the L_Port to which it is directed. It is used only in Arbitrated Loops.
LPE Loop Port Enable; a primitive sequence transmitted by an L_Port to enable an L_Port that has been bypassed with the LPB. It is used only in Arbitrated Loops.
L_Port Node Loop port; a port supporting the Arbitrated Loop protocol. It appears as the part of the output of a switchShow Telnet command.
LPSM Loop Port State Machine; logic that monitors and performs the tasks required for initialization and access to the loop. It is maintained by an L_Port to track behavior through different phases of loop operations.
LR Link Reset; a primitive sequence used during link initialization between two N_Ports in point-to-point topology, or an N_Port and an F_Port in fabric topology. The expected response is an LRR.
LRR Link Reset Response; a primitive sequence during link initialization between two N_Ports in point-to-point topology, or an N_Port and an F_Port in fabric topology. It is sent in response to an LR, and expects a response of Idle.
LWL Long wavelength fiber-optic; connector is color-coded blue, and is based on 1,300-millimeter lasers supporting 1.0625-gigabit-per-second link speeds.
MAN Metropolitan Area Network.
Mbps Megabits per second.
MBps Megabytes per second.
Metric A relative value assigned to a route to aid in calculating the shortest path.
MIA Media Interface Adapter; a device that converts optical connections to copper ones.
MIB Management Information Base; an SNMP structure for device management that contains an abstraction of configuration and device information.
MRK Mark Primitive Signal; used only in Arbitrated Loop, it is transmitted by an L_Port for synchronization and is vendor specific.
MTBF Mean Time Between Failures; an expression of a unit of time indicating the longevity of a device.
Multicast A restricted broadcast to a subset of the N_Ports on the network.
Multimode A fiber-optic cabling specification that allows up to 500-meter distances between devices.
Name Server/Service See SNS.
NAS Network Attached Storage; a disk array connected to a controller that gives access to a LAN Transport.
NDMP Network Data Management Protocol; used for tape backups without using server resources.
NIC Network Interconnect Card.
NL_PortNode Loop port; a port supporting the Arbitrated Loop protocol.
Node A fibre channel device that supports one or more ports.
Node name A 64-bit unique identifier assigned to a fibre channel node.
Non-OFC A category of laser transceiver that does not require open fibre control due to its low intensity.
Nonparticipating Mode This mode is entered if there are more than 127 devices on a loop, and an AL_PA cannot be acquired.
NOS Non-Operational Primitive Sequence; used during link initialization between two N_Ports in the point-to-point topology, or an N_Port and F_Port in the fabric topology. It is sent to indicate that the transmitting port has detected a link failure or is offline. An OLS is the expected response.
N_Port A fibre channel port in a fabric or point-to-point connection.
OFC Open Fiber Control; a method used to enable and disable laser signaling for higher-intensity laser transceivers.
OLS Offline Primitive Sequence; this is used during link initialization between two N_Ports in a point-to-point topology or an F_Port and an N_Port in a fabric. It is sent to indicate that the transmitting port is attempting to initialize a link, has recognized the NOS primitive sequence, or is going offline. The expected response to an OLS is an LR.
OLTP OnLine Transaction Processing.
Operation An FC-2 term that refers to building blocks.
OPN Open Primitive Signal; this applies only to Arbitrated Loop, and is sent by an L_Port that has won the arbitration process to open communication with one or more ports on the loop.
Ordered set A group of low-level protocols used to manage frame transport, initialization, and media access, and to distinguish fibre channel control information from data.
Originator The N_Port that originated an exchange.
Out-of-band Transmission of management protocol outside of the fibre channel network, usually over Ethernet.
OX_ID Originator Exchange Identifier; a 2-byte field in the frame header used by the originator of an exchange to identify frames as being part of an exchange.
Parallel The simultaneous transmission of data bits over multiple lines.
Participating Mode The normal operating mode for an L_Port that has acquired an AL_PA on a loop.
Passive copper A low-cost copper fibre channel connection allowing distances up to 13 meters (14 yards) between devices.
PBC Port Bypass Circuit; a circuit in hubs or a disk enclosure to open or close a loop to add or remove nodes.
PLDA Private Loop Direct Attached; a logical loop.
PLOGI A port-to-port login process where initiators establish sessions with targets.
Point to Point A dedicated fibre channel connection between two devices.
Port A fibre channel entity that connects a node to the network.
Port Log A record of all activity on a switch, kept in volatile memory.
Port Log Dump A view of what happens on a switch from the switch's point of view. This is the command used to read the Port Log.
Port name A unique 64-bit character identifier assigned to a fibre channel port.
POST Power On Self Test; a routine that the switch performs to test its components.
Primitive sequence Ordered sets that indicate or start state changes on the transport medium and require at least three consecutive occurrences to trigger a response.
Primitive signals Ordered sets that indicate actions or events and require just one occurrence to trigger a response. Idle and R_RDY are used in all three topologies, ARB, OPN CLS, and MRK are in Arbitrated Loop.
Private device A device that supports loop and can understand 8-bit addresses but cannot log into the fabric.
Private loop An Arbitrated Loop with no fabric attachment.
Private loop device An Arbitrated Loop device with no fabric attachment.
Private NL_Port An NL_Port on a public or private loop; it only communicates with other ports on the loop, not with the fabric.
PSU Power Supply Unit.
Public device A device that supports loop and can also log into the fabric.
Public loop An Arbitrated Loop attached to a fabric switch.
Public loop device An Arbitrated Loop device that supports fabric login and services.
Public NL_Port An NL_Port that may communicate with other ports on the loop as well as through an FL_Port to other N_Ports on the fabric.
Qlogic A brand of host bus adapter.
QoS Quality of Service.
Queue A mechanism for each AL_PA address that allows for collecting frames prior to sending them to the loop.
QuickLoop A Brocade software product that allows multiple ports on a switch to create a logical PLDA. Devices connected via QuickLoop will appear to each other as if they were on the same Arbitrated Loop.
RAID Redundant Array of Independent Disks; disks look like a single volume to the server, and are fault-tolerant either through mirroring or parity checking.
R_A_TOV Resource Allocation Time Out Value; used to timeout operations that depend on the maximum allowable time a frame could be delayed in the fabric and still be delivered.
Receiver A device that does detection and signal processing.
Redundancy Having multiple occurrences of a component to maintain high availability.
Remote switch An optional product using a Computer Network Technology gateway over ATM.
Repeater A circuit that uses recovered clock to regenerate and transmit an outbound signal.
Responder The N_Port with which an Exchange originator wishes to communicate.
Retimer A circuit that uses an independent clock to generate outbound signals.
Route A path between two switches.
R_RDY Receiver Ready; a primitive signal indicating that the port is ready to receive a frame.
RSCN Registered State Change Notification; a switch function that allows notification to registered nodes if a change occurs either with or within the fabric.
R_T_TOV Receiver Transmitter Timeout Value; used by the receiver logic to detect loss of synchronization between transmitters and receivers. RX_ID Responder Exchange Identifier; A 2-byte field in the frame header used by the responder of the Exchange to identify frames as being part of a particular exchange.
S_ID Source Identifier; A 3-byte field in the frame header used to indicate the address identifier of the N_Port from which the frame was sent.
SAN Server Storage or Area Network; a network linking computing devices to disk or tape arrays and other devices over fibre channel.
SCR State Change Registration.
The command used by devices to register to receive RSCNs.
SCSI Small Computer Systems Interface; A parallel bus architecture and a protocol for transmitting large data blocks to a distance of 15-25 meters.
SCSI-2 An updated version of the SCSI bus architecture.
SCSI-3 A SCSI standard that defines transmission of SCSI protocol data over serial links.
SEQ_ID Sequence Identifier; a 1-byte field in the frame header used by the responder of the Exchange to identify frames as being part of a particular Exchange.
Sequence A group of related frames transmitted unidirectionally from one N_Port to another.
Sequence initiator The N_Port that begins a new Sequence and transmits frames to another N_Port.
Sequence recipient The N_Port to which a particular Sequence of data frames is directed.
SERDES SERializing/DESerializing circuitry; a circuit that converts a serial bit stream into parallel characters, and vice-versa.
Serial The transmission of data bits in sequential order over a single line.
Server A central computer that processes end-user applications or requests.
SES SCSI Enclosure Services; a subset of the SCSI protocol used to monitor temperature, power, and fan status for enclosed devices.
SilkWorm A brand name for the Brocade family of switches.
Single mode A fiber-optic cabling specification that provides up to 10-km (6.8-mile) distances between devices.
sLink service Facilities used between an N_Port and the fabric, or between two N_Ports for login, sequence/exchange management, and maintaining connections.
SMI Structure of Management Information; a notation for setting or retrieving SNMP management variables.
SNMP Simple Network Management Protocol; A TCP/IP protocol that was designed for management of networks over TCP/IP, using agents and stations.
SNS Simple Name Server (or Service); the service provided by a fabric switch that stores names, addresses, and attributes related to fibre channel objects, and can cache the information for up to 15 minutes. This is also known as a directory service.
SOF Start Of Frame; a group of ordered sets that marks the beginning of a frame and indicates the class of service the frame will use.
SoIP SCSI over IP.
SONET Synchronous Optical Network; a standard for optical networks providing building blocks and flexible payload mappings.
Special character A special 10-bit character that does not have a corresponding 8-bit value but is still considered valid. The special character is used to indicate that a particular transmission word is an ordered set. This is the only character to have five 1s or 0s in a row.
SRM Storage Resource Management; the management of disk volumes and any file resources.
Stealth mode A method used in some switches to have them work similar to Brocade switches using QuickLoop.
Storage A device used to store data; such as a disk or tape.
Store-and-forward A switching technique that requires buffering an entire frame before a routing decision is made.
Striping A RAID technique for writing a file to multiple disks on a block-by-block basis, with or without parity.
Switch A fabric device providing full bandwidth per port and high-speed routing of data via link-level addressing.
SWL Short WaveLength fiber optic; connector is color-coded black, and is based on 850-mm lasers supporting 1.
0625-Gbps link speeds.
T11 A standards committee chartered with creating standards for data movement to and from central computers.
Tachyon A chip developed by Hewlett-.
Packard, and used in various devices. This chip has FC-0 through FC-2 on one chip.
Target A disk array or a tape on a fibre channel network.
TCP/IP Transmission Control Protocol over Internet Protocol.
Telnet A virtual terminal emulation used with TCP/IP.
Tenancy Possession of an Arbitrated Loop by a device to conduct a transaction.
Time server A fibre channel service that allows for the management of all timers.
Topology The physical or logical arrangement of devices in a networked configuration.
TPC Third Party Copy; a protocol for performing tape backups without using server resources.
Transceiver A device that converts one form of signaling to another for transmission and reception; in fiber optics it means optical to electrical.
Translative mode Allows public devices to communicate with private devices across a fabric.
Transmission character A valid or invalid character transmitted serially over fibre.
Transmission word A string of four consecutive transmission characters.
Trap An SNMP mechanism for agents to notify the SNMP management station of significant events.
TTL Time To Live; the number of seconds an entry exists in cache before it expires.
Tunneling A technique for making two different networks interact where the source and destination hosts are on the same type of network, but there is a different network in between.
U_Port Universal Port; a port that can operate as a G/E/F/FL_Port. All SilkWorm 2xxx series of switches contain Universal Ports to allow any device to connect to any port. Selection of actual port type is automatic.
ULP Upper Level Protocol; the protocol that runs on top of fibre channel through the FC-4 layer.
Typical protocols are SCSI, IP, HiPPI, and IPI.
Unicast A routing method that provides one or more optimal path(s) between any two switches in the fabric.
VAR Value Added Reseller.
VCSEL Vertical Cavity Surface Emitting Laser; an improved and more reliable type of laser.
Virtual circuit A one-way path between N_Ports that allows fractional bandwidth.
WAN Wide Area Network.
WDM Wavelength Division Multiplexer; allows multiple wavelengths to be combined or filtered on a single cable.
World-Wide Name A registered 64-bit unique identifier for nodes and ports in a fabric.
Zoning A feature in fabric switches or hubs that allows segmentation of a node by physical port, name, or address.