T 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| Numerical Listing| T1 A digital carrier facility used to transmit digital signals at 1.544 Mbps using 24-channel pulse-code modulation. T3 A digital carrier facility used to transmit digital signals at 44.74 Mbps. TA (Telecommunications Administration) Formerly called PTT (Postal, Telephone and Telegraph), a TA is an agency in a European or Asian country that is usually a government-run monopoly. It is responsible for all postal, telegraph and telephone services. It also has certain regulatory functions for telecommunications, such as providing specifications for modems and certifying that equipment may connect to the telephone network. In some countries, the TA also provides its own line of equipment, e.g., modems. TAs are undergoing varying amounts of structural change. TA (Terminal Adapter) An interfacing device for an Integrated Services Digital Network (ISDN) environment. It enables non-ISDN terminals to connect at the physical layer. TAPI (Telephony Application Programming Interface) An interface standard from Microsoft and Intel that brings a well-defined computer/telephone application programming interface to the desktop. TAPI’s initial release offered drivers that could be added to Microsoft’s Windows 3.1. The desktop linkage for TAPI can be accomplished via serial RS-232 interfaces. Additionally, it also allows for a board associated with the telephone to plug into the desktop computer's bus. The telephone station does not disappear from the desktop for several reasons (e.g., computer and application up-time, and handset requirement). The stable application programming interfaces that exist between Windows and the nx64 Kbps circuit-switching systems are not limited to voice; they can accommodate data, images and video. TOP OF PAGE Tariff The formal process whereby services and rates are established by and for communications common carriers. Carriers submit tariffs to the appropriate regulatory agencies, which then review, amend and then approve or disallow them. Tariff No. 12 AT&T’s tariff Custom Designed Integrated Services offering to large users whose requirements were ostensibly unique enough to require a custom network design and price. The custom designs included voice and data requirements; each is subject to FCC approval. TAXI (Transparent Asynchronous Transmitter/Receiver Interface) A 100-Mbps multimode fiber interface. TCM (Thermal Conduction Module) The basic building block technology of the IBM 308X, 3090 and ES/9000. The TCM is a sealed container enclosing a multiple-chip carrying substrate amid chip interconnection structure. TCO (Total Cost of Ownership) The useful life-cycle cost of a system. In practice, in addition to hardware and software configuration prices, maintenance costs are added as computer system TCO factors. TCP/IP (Transaction Control Protocol/Internet Protocol) A set of protocols covering (approximately) the network and transport layers of the seven-layer Open Systems Interconnection network model. TCP/IP was developed over a 15-year period under the auspices of the Department of Defense. It has achieved de facto standard status, particularly as higher-level layers over Ethernet. TCP/IP implementations are available on products from more than 80 vendors, including IBM, Digital Equipment Corp., AT&T, Data General and Sun Microsystems, AT&T, Apollo, Data General and Sun Microsystems. But its exclusion from Systems Application Architecture means that IBM views TCP/IP as a special-purpose protocol set. The biggest issue for TCP/IP is potential migration to the International Standards Organization protocols for Layers 3 and 4. TOP OF PAGE TDM (Time Division Multiplexing) A data, voice and video communications technique that interleaves several low-speed signals into one high-speed transmission. TDMA (Time Division Multiple Access) A frequency allocation technique based on allotting discrete time slots to users, permitting many simultaneous transmissions. Team Data Management (TDM) Systems for managing computer-aided design files and the activities of small work groups. Telco A contraction of the term "telephone company." It generally refers to the local exchange carrier. Telecommuting Any significant portion of working hours spent at a remote site using communications lines to send and receive information, interact with customers and peers, and deliver work product. Telephony The science of transmitting voice, data, video or image signals over a distance greater than what you can transmit by shouting. The word derives from the Greek for "far sound." For the first hundred years of the telephone industry's existence, the word telephony described the business the nation's phone companies were in. It was a generic term. In the early 1980s, the term lost fashion and many phone companies decided they were no longer in telephony, but in telecommunications -- a more pompous sounding term that was meant to encompass more than just voice. The pomposity of the word may have added some value to the stock of telecommunications companies. In the early 1990s, as computer companies started entering the telecommunications industry, the word telephony was resurrected. And in a white paper on Multimedia from Sun Microsystems, the company said that telephony refers to the integration of the telephone into the workstation. For instance, making or forwarding a call will be as easy as pointing to an address book entry. Caller identification (if available from the telephone company) could be used to automatically start an application or bring up a database file. Voicemail and incoming faxes can be integrated with e-mail (electronic mail). Users can have all the features of today's telephones accessible through their workstations, plus the added benefits provided by integrating the telephone with other desktop functions. See also COMPUTER TELEPHONY. Telpak Telpak is a discount schedule for volume voice-grade channel users. Terabyte One trillion bytes. Text Retrieval Software used for finding units of textual information such as documents by matching a user's search terms to those in a full-text index derived from the collection of textual units. Third Generation The class of client/server office systems introduced beginning in 1989, including IBM’s OfficeVision, Digital Equipment Corp.’s ALL-IN-1 Phase II and Hewlett-Packard’s NewWave Office. Third-generation office systems are targeted at the knowledge worker and promise to deliver dramatic improvements in usability as well as entirely new classes of applications with mission-critical implications. Three-Schema Architecture A framework for managing access to data that involves three layers or schemata: the external or programmatic view, the conceptual or data administration view and the internal or database administration view. Such ideas were developed by an American National Standards Institute/Scalable Processor Architecture subcommittee in 1971 but have received little practical implementation by database management system vendors (Cincom being an exception). The principle is that the conceptual schema consists of business rules derived from a semantic data model, which provides independence between programs and data structures. The emphasis has now shifted to computer-aided software engineering tools and "repository" standards. TOP OF PAGE Throughput A computer term for the volume of work or information flowing through a system. Particularly meaningful in information storage and retrieval systems, in which throughput is measured in units such as accesses per hour. TIFF (Tag Image File Format) A de facto standard format for image files. Tightly Coupled Multiprocessing A configuration in which all processors share a single pool of memory. Time-Sharing An operating environment that supports many users by allocating small time slices so that each user appears to have the dedicated resources of the machine. TIMS (Text Information Management Systems) The genre of products that combine content-based retrieval and document database functions. TPC (Transaction Processing Council) An organization that has developed several standardized transaction processing benchmarks, among which are TPC-A, TPC-B, and TPC-C. The TPC prohibits testing systems that are specially optimized for benchmarking or lack real-world applicability. TPC-A (Transaction Processing Council — Test A) A revised and superior version of the debit/credit on-line transaction processing (OLTP) benchmark. Ratified in late 1989, it came into widespread use in 1990. The major improvements in TPC-A were the requirements for full disclosure and the inclusion of the front-end network and terminals. TPC-A is intended to replace debit/credit as the only industrywide measure for OLTP performance and price/performance. It is a good test since it measures end-to-end performance, but it still is only one test reflecting a single type of transaction. TPF2 (Transaction Processing Facility 2) TPF2 is a low-function, high-cost set of control blocks and macro instructions that is positioned as IBM’s highest-performance transaction-processing environment. Its users include many banks and airlines. TPS (Transactions Per Second) A term used in computing many transaction processing metrics, such as dollars per tps; it is usually reckoned in TPC-A. The metric used in evaluating on-line transaction processing system performance. Tps are typically measured under conditions of a specified percentage of standard transactions completed in under a specified response time. TQC (Total Quality Control) A theory of quality whereby the maker of the part has responsibility for the quality of that part. Traditional Processing The availability of traditional and basic data processing facilities at the midrange system. Examples include sequential and keyed files, compilers such as COBOL, FORTRAN, PL/I, BASIC and C, interactive access, batch processing, multiprocessing and multitasking. Transaction A logical update that takes a database from one consistent state to another. TOP OF PAGE Transaction Feed The capability of passing to the mainframe, midrange system transactions predetermined for MVS/CICS (Multiple Virtual Storage/Customer Information and Control System) or VM/CICS (Virtual Machine/Customer Information and Control System) processing with replies returned to the midrange system user. The IBM "intersystem communication" facility of CICS could be the technique used for implementation. Transaction Logging A concept in which a detailed record is kept of all operations in a transaction; in case of a failure, the transaction could be backed out and the former state reconstructed. Transaction Monitor A subsystem that ensures that all transactions against a database leave it in a consistent state or, in case of a transaction failure, returns the database to its pre-transaction state. Transport Layer In the Open Systems Interconnection model, the network processing entity responsible, in conjunction with the underlying network, data link and physical layers, for the end-to-end control of transmitted data and the optimized use of network resources. TRN (Token Ring Network) A local-area network (LAN) topology and protocol in which all stations actively attached to the ring listen for a broadcast token or supervisory frame. Stations wishing to transmit must receive the token before doing so, and when done must pass the token to the logical next station on the ring. IBM promotes TRN as its strategic LAN architecture. TSAPI (Telephony Services Application Programming Interface) A computer telephony integration (CTI) application programming interface developed by Novell and AT&T that provides a client/server implementation and supports first- and third-party call control. The major benefit of third-party call control is that, via the command link to the switch, it is possible to control calls between third parties (much like an operator does today). This permits CTI applications to provide multiparty services, call routing based on automatic number identification and other advanced features. However, TSAPI requires a Novell NetWare networking environment. TSAPI does not require additional hardware in each PC, but does require a server CTI connection to the private branch exchange equipment. TSO (Time-Sharing Option) TSO is the name originally given to IBM’s compatible extension of MVS background facilities into foreground execution. The name has stuck, although TSO is no longer an option in MVS. TUBA (TCP/UDP Over Big Address) A proposal to expand the Internet’s TCP/IP address-space limit. The TUBA proposal would use the OSI protocols to attach to the existing Internet applications layer. Two-Phase Commit Method for coordinating a single transaction across two or more DBMSs or other resource managers. Two-phase commit guarantees the logical integrity of data by ensuring that transaction updates are finalized in all of the separate databases or are fully backed out of all participating databases, i.e., all or nothing based on transaction boundaries. Two-phase commit is a necessary component of distributed database and is implemented in "transaction management" software, which may be part of a database management system, on-line transaction processing monitor, or front-end application tool. TOP OF PAGE Two-Phase Commit Protocol Handshaking semantics across more than one participating node or database on a network involved in a transaction update such that, if a failure occurs at any point in the middle, all record updates are automatically rolled back. Comments? Questions? Entire contents Copyright © 1997, 1998 by Gartner Group, Inc. All rights reserved. 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