SNIA Online Dictionary

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T10	[SCSI] Short name for the ANSI INCITS T10 technical committee.
T11	Short name for the ANSI INCITS TC T11 committee.
T13	[Standards] Short name for the ANSI INCITS T13 technical committee.
table routing method	[SCSI] A method used by SAS expanders for routing connection requests when multiple devices are accessible through a single SAS switch port.
tabular mapping	[Storage System] A form of mapping in which a lookup table contains the correspondence between the two address spaces being mapped to each other. If a mapping between two address spaces is tabular, there is no mathematical formula that will convert addresses in one space to addresses in the other. See algorithmic mapping, dynamic mapping.
tampering	[Data Security] An unauthorized modification that alters the proper functioning of a device, system or communications path in a manner that degrades the security or functionality it provides.
tape	[Storage System] A removable storage element containing a flexible substrate stored on a reel used as a storage medium. The data on a tape is accessed by a tape drive.
tape autoloader	[Storage System] A robotic tape media handler in which media is sequentially loaded and unloaded by the robot. The term tape autoloader is typically used to indicate a single drive library that may have a sequential operation mode.
tape cartridge	[Storage System] A tape with its carrier. A tape cartridge may also contain other storage elements (e.g., a medium auxiliary memory).
tape drive	[Storage System] A storage device that reads and writes data on tapes. Unlike disks, tapes use implicit data addressing. See disk.
tape eject slot	[Storage System] An entry/exit slot in a tape library.
tape library	[Storage System] A storage device that provides addressable access to multiple tape cartridges, typically via multiple tape drives. A robotic media handler is used to move tape cartridges between the tape drives, tape slots, and tape entry/exit slots.
tape slot	[Storage System] A physical location used to hold a tape cartridge when not in a tape drive.
tape virtualization	[Storage System] The application of storage virtualization to create a virtual tape or a virtual tape library.
target	[SCSI] The endpoint that receives a SCSI I/O command sequence. See initiator, LUN, target port identifier.
target NVMe_Port	[Fibre Channel] NVMe-Port which is the NVM subsystem port for an NVMeoFC association.
Target of Evaluation	[Data Security] An IT product or system and its associated guidance documentation that is the subject of evaluation. This term is most commonly associated with ISO 15408.
target port identifier	[SCSI] The interconnect address of a target or controller.
Target Session Identifying Handle	[iSCSI] An identifier, assigned by the iSCSI target, for a session with a specific named initiator.
TB / TByte	[Computer System] Shorthand for Terabyte.
Tbit	[General] Shorthand for Terabit.
TCG	[Data Security] Acronym for Trusted Computing Group.
TCO	[General] Acronym for Total Cost of Ownership.
TCP	[Network] Acronym for Transmission Control Protocol.
TCP Offload Engine	[Network] A technology for improving TCP/IP performance by offloading TCP/IP processing to a Network Interface Card.
TCP/IP	[Network] Shorthand for the suite of protocols that includes TCP, IP, UDP, and ICMP. This is the basic set of communication protocols used on the Internet.
Tebibit	[General] Shorthand for 1,099,511,627,776 (240) bits. Binary notation is most commonly used for semiconductor memory sizes. See also Terabit.
Tebibyte	[General] Shorthand for 1,099,511,627,776 (240) bytes. Binary notation is most commonly used for semiconductor memory sizes. See also Terabyte.
technical controls	[Data Security] Security controls (i.e., safeguards or countermeasures) for an information system that are primarily implemented and executed by the information system through mechanisms contained in the hardware, software, or firmware components of the system. [NIST Special Pub 800-53]
Technical Working Group	[Standards] A SNIA working group in which specific technical work is undertaken, protected by the SNIA IP Policy. Within the SNIA, technical work for standards development is conducted by volunteer technologists from member companies. The TWGs report to the SNIA Technical Council, which in turn reports to the SNIA Board.
Terabit	[General] Shorthand for 1,000,000,000,000 (1012) bits. The SNIA uses the base 10 convention commonly found in I/O-related and scientific literature rather than the base 2 convention (1,099,511,627,776, i.e., 240) common in computer system and software literature. See also Tebibit.
Terabyte	[Computer System] Shorthand for 1,000,000,000,000 (1012) bytes. The SNIA uses the base 10 convention commonly found in I/O-related and scientific literature rather than the base 2 convention (1,099,5111,627,776, i.e., 240) common in computer system and software literature. See also Tebibyte.
test system	[Storage System] A collection of equipment used to perform a test on a system under test. See also solution under test and system under test.
theoretical capacity	[Storage System] The total number of bytes on the physical media. Theoretical capacity includes addressable capacity, ECC (error correcting code) data, remap areas, and other capacity used for the operation of the device. See addressable capacity.
thin provisioning	[Storage System] A technology that allocates the physical capacity of a volume or file system as applications write data, rather than preallocating all the physical capacity at the time of provisioning.
third party authentication	[Data Security] Reliance on an authentication service, such as a RADIUS server, that is separate from (or external to) the entities of an authentication transaction.
third party copy	[Data Recovery], [Management], [SCSI] A technique for performing backups using minimal host resources by copying data directly from the source to the destination without passing through a host.
threat	[Data Security] Any possible intentional action or series of actions with a damaging potential to any of the stakeholders, the facilities, operations, the supply chain, society, economy, or business continuity and integrity [ISO 28004-1:2007].
threat monitoring	[Data Security] Analysis, assessment, and review of audit trails and other information collected for the purpose of searching out system events that may constitute violations of system security.
throughput	[Computer System] A deprecated synonym for data transfer capacity.
TiB / TiByte	[General] Shorthand for Tebibyte.
Tibit	[General] Shorthand for Tebibit.
tiered storage	[Storage System] Storage that is physically partitioned into multiple distinct classes based on price, performance or other attributes. Data may be dynamically moved among classes in a tiered storage implementation based on access activity or other considerations.
time server	[Network] An intelligent entity in a network that enables all nodes in the network to maintain a common time base within close tolerances.
TLC	[Hardware] Acronym for Triple-Level Cell
TLS	[Data Security] Acronym for Transport Layer Security.
TNC	[Network] Acronym for Threaded Neil Councilman, a type of coaxial cable connector. Specifications for TNC style connectors are defined in MIL-C-39012 and MIL-C-23329.
TOE	[Network], [Data Security] 1. Acronym for TCP Offload Engine. 2. Acronym for Target of Evaluation.
token ring	[Network] 1. A network in which each node's transmitter is connected to the receiver of the node to its logical right, forming a continuous ring. Nodes on a token ring network gain the right to transmit data by retaining a token (a specific unique message) when they receive it. When a node holding the token has transmitted its allotment of data, it forwards the token to the next node in the ring. 2. A LAN protocol for token ring networks governed by IEEE Standard 802.3 that operates at speeds of 4 Mbits/second and 16 Mbits/second.
topology	[Network] 1. The logical layout of the components of a computer system or network and their interconnections. Topology deals with questions of what components are directly connected to other components from the standpoint of being able to communicate. It does not deal with questions of physical location of components or interconnecting cables. 2. The communication infrastructure that provides Fibre Channel communication among a set of PN-Ports (e.g., a Fabric, an Arbitrated Loop, or a combination of the two).
Total Cost of Ownership	[General] The comprehensive cost over its lifetime of a particular capability such as data processing, storage access, file services, etc. Total Cost of Ownership (TCO) includes acquisition, environment, operations, management, service, upgrade, loss of service, and residual value.
TPC	[Data Recovery], [Management] Acronym for Third Party Copy.
track	[Hardware] A portion of a recording address (see CHS) on an HDD that defines the combination of the cylinder and head.
transceiver	A transmitter and receiver combined in one package.
transformation	[Long-Term Retention] A type of migration in which a format or representation change occurs during the movement of data or information. Transformation involves possible information loss, since newer formats may be incapable of capturing all the functionality of the original format, or the migration system may be unable to interpret all the nuances of the original format.
Translate Domain	[Fibre Channel] A domain presented by a Translate Domain Switch.
Translate Domain switch	[Fibre Channel] A Fibre Channel Switch within an Inter-Fabric Router that is created for each set of Proxy Nx_Ports whose corresponding Native Nx_Ports exist within a set of Native Fabrics.
transmission character	[Network] Any encoded character (valid or invalid) transmitted across a physical interface. Valid transmission characters are specified by the standard defining the transmission code and include data characters and special characters.
transmission code	[General], [Network] 1. A means of encoding data to enhance its transmission characteristics. 2. A byte-oriented transmission code specified by FC-FS-2 for 1/2/4/8 GFC, with valid data bytes and special codes encoded into 10-bit Transmission Characters according to the 8B10B encoding. 3. A word-oriented transmission code specified by 10GFC, with 64 bits of data and special codes encoded into a 66-bit transmission unit according to the 64/66 encoding.
Transmission Control Protocol	[Network] The Internet connection oriented network transport protocol, which provides a reliable delivery service.
transmission word	[Fibre Channel] A string of four contiguous transmission characters aligned on boundaries that are zero modulo 4 from a previously received or transmitted special character. Fibre Channel transmission and reception operates in transmission word units when using 8B/10B encoding.
transmitter	1. The portion of a Link_Control_Facility that converts valid data bytes and special codes into transmission characters using the rules specified by the transmission code, converting these transmission characters into a bit stream, and transmitting this bit stream on an optical or electrical transmission medium. 2. An electronic circuit that converts an electrical logic signal to a signal suitable for an optical or electrical communications media.
transparent failover	[Computer System] A failover, not visible to external components of a system, of one component of that system to another component of that system. Often used to refer to paired disk controllers, one of which exports the other's virtual disks at the same addresses after a failure. See non-transparent failover.
Transport Layer Security	[Data Security] A protocol suite defined by the IETF that provides privacy and data integrity between two communicating applications, using higher-level protocols that can layer on top of the TLS protocol transparently. There are multiple versions of TLS, which are not compatible with each other, and early versions are considered less secure and should not be used. Multiple SNIA specifications leverage TLS as an important security mechanism; to ensure both security and interoperability, SNIA has published the SNIA TLS specification for storage systems (also ISO/IEC 20648) to identify specific requirements and guidance for TLS when it is used in conjunction with these SNIA specifications.
trap	[Management] A type of SNMP message used to signal that an event has occurred. Trap delivery to recipients uses UDP and is not completely reliable. See best effort.
triaxial cable	[Network] An electrical transmission medium consisting of three concentric conductors separated by a dielectric material with the spacings and material arranged to give a specified electrical impedance. See coaxial cable.
trim	[Storage System] A method by which the host operating system may inform a storage device of blocks of data that are no longer in use and can be reclaimed. Many storage protocols support this functionality via various names, e.g., ATA TRIM and SCSI UNMAP. See also garbage collection.
Triple-Level Cell	[Hardware] A memory cell that stores three bits of data.
trojan horse	[Data Security] Malware that masquerades as a benign application containing malicious logic that allows the unauthorized collection, falsification, or destruction of data.
trust	[Data Security] Belief in the reliability, truth, ability, or strength of someone or something. A trusted system is believed to have the ability to function as expected and to not misbehave.
Trusted Computing Group	[Data Security] A not-for-profit organization formed to develop, define, and promote open standards for hardware-enabled trusted computing and security technologies, including hardware building blocks and software interfaces, across multiple platforms, peripherals, and devices.
trusted system	[Data Security] A system that may be used for processing of sensitive or classified information, that employs sufficient hardware and software integrity measures to assure that it performs according to its documented specification and acts in a predictable manner. Such a system is developed in accordance with security criteria and evaluated by these criteria.
TSIH	[iSCSI] Acronym for Target Session Identifying Handle.
tunneling	[Data Security] A technology that enables one network protocol to send its data via another network protocol's connections. Tunneling works by encapsulating the first network protocol within packets carried by the second protocol. A tunnel may also encapsulate a protocol within itself (e.g., an IPsec gateway operates in this fashion, encapsulating IP in IP and inserting additional IPsec information between the two IP headers).
TWG	[Standards] Acronym for Technical Working Group.