Technical Glossary

 

3DES	Triple Data Encryption Standard
AAC	A Dolby audio compression scheme, IEC standard 13818-7 for MPEG-2, and IEC 14496-3 for MPEG-4.
AAL5	ATM Adaptation Layer Five. An encapsulation of packets into ATM  frames. ITU-T Recommendation I.363, March 1993. Connection oriented but variable bit rate, often used for IP datagrams.
AC-3	Dolby Digital Surround Sound. Five audio channels plus sub woofer. Sometimes called 5.1 channels. Used for NTSCDVD-Video.
Access Rate	The speed, in bits per second, at which data is transmitted between the end user and the network.
Adaptive Equalization	Receiver technique that compensates for distortions in transmission media.
ADC	Analog to Digital Converter
ADSL	Asymmetric Digital Subscriber Line. Offers higher download speed than upload speeds and is usually configured to deliver up to six megabits(Mbps) of data per second.
ADM	Add Drop Multiplexor. Splits out part of a SONET link.
ADPCM	Adaptive Differential Pulse Code Modulation. Popular audio encoding (telephone quality at 32 Kbps).
ADSL	Asymmetric Digital Subscriber Line. Twisted-pair modem technology that achieves data rates of up to 8 Mbps downstream to the subscriber, and up to 1 Mbps upstream to the network at distances up to 18,000 feet.
AFD	All Format Decoder
AFE	Analog Front End
AGP	Accelerated Graphics Port. Located on new PCs between CPU and display controller.
AGT	A force of substance that causes change.
Aggregator	Any number of services or systems that aggregate particular items for convenient use by customers.
AID	Access Identifier. Start of Tut HomeRun packet, for collision detection.
Analog Decoder	A circuit that performs decoding using analog circuit techniques rather than digital circuit techniques.
ANSI	American National Standards Institute
API	Application Programming Interface.  A specification of a software interface, usually in terms of data structures and function declarations.
APS	Analog Protection System. Prevents easy piracy, such as Macrovision, which prevents analog copies on VHS tapes.
ARL	Acceptable Reliability Level
ARQ	Automatic Repeat reQuest. Using link level sequence numbers for retransmission.
ASD	Advanced Streaming Descriptor. NetShow encoder config files.
ASIC	Application Specific Integrated Circuit.
ATAPI	AT Attachment Packet Interface
ATL	Active Template Library
ATM	Asynchronous Transfer Mode. A family of specifications for network connection at speed like 155 Mbps, 622 Mbps, and higher. Based on tiny cells, assembled into frames or bit streams.
ATSC	Advanced Television Systems Committee
ATU	ADSL Transceiver Unit. ATU-C is the central office end, and ATU-R the "remote" (subscriber) end.
AV/C	Audio Video Control, (part of 1394).
AVT	Audio Video Transport
Backbone	A central very high-speed, fiber network transmission path used for high-volume network-to-network connections.
Back Channel	A means of communication from users to content providers.
Bandwidth	The range of frequencies of interest on a channel.
BAR	Base Address Register.
BASCS	Broadcom Advanced Server Control System.
BASP	Broadcom Advanced Server Program.
BCC	Binary Convolutional Code
BEB	Binary Exponential Backoff. Collision resolution on Ethernet.
BIST	Built In Self Test
BORSCHT	Battery, Over voltage, Ringing, Supervision, Coding, Hybrid, Test
BPS	Bits per second. The number of bits passing a point every second.
Broadband Communications	Data transmissions at speeds of greater than 1.5 Mbps.
BRI	Basic Rate Interface. The basic unit of ISDN service, usually 56 Kbps or 64 Kbps.
Bridge	A device that connects two networks as a seamless single network using the same networking protocol.
Cable Modem	A data modem that uses the bandwidth within a cable TV system, which can have speeds up to 80 times faster than an ISDN line or six times faster that a dedicated T1 line.
Cache	Local or temporary storage.
CAP	Carrierless Amplitude and Phase. Also called Carrierless AM/PM (Amplitude modulation and phase modulation). A modulation scheme for xDSL that shipped earlier than the official standard DMT. The notation n-CAP means log2(n) bits per baud.
Carrier Hotel	Collocation involves companies - either Incumbent Local Exchange Carriers (ILECs) or independent firms -- providing space to house telecommunications equipment.
CASE	Computer Aided Software Engineering, Common Application Service Element.
CBC	Cipher Block Chaining. A mode of DES.
CBDong	Card Bus "Dongle" board, with magnetics and LED.
CBNIC	CardBus Network Interface Card reference board.
CBR	Constant Bit Rate, committed bandwidth reservation.
CCD	Charge Coupled Device. Common digital camera technology.
CDU	Circular buffer Data Unit
CDV	Processing of data stream to greatly reduce(compress) the data bandwidth required to transmit video images.
CEBus	Consumer Electronics Bus. "Standard" powerline net, about 10 Kbps.
Cell	53 byte units switched by ATM technology.
CES	Consumer Electronics Show
CFID	ConFiguration IDentifier (device and vendor ids for a PCI device).
CHAP	Challenge Handshake Authentication Protocol. For PPP link (usually Dial-In) security.
CIF	Common Interchange Format. A popular video encoding, often 352x288 pixels, about half of CCIR-601.
CLEC	Competitive Local Exchange Carrier.
CLSID	Class Identifier. String of hex numbers for ActiveX.
CMIC	Cable Modem Information Center, configuration Management Information Center.ISO proposal for network management.
CMIP	Common Management Interface and Protocol. ISO proposal for network management.
CMOS	Complementary Metal Oxide Semiconductor. Technology used to manufacture silicon integrated circuits.
CMTS	Cable Modem Termination System. The cable headend device which serves as a bridge between a DOCSIS cable data modem and the internet.
CNIC	Composite Network Interface Card. An AFE  in 2-3.5 MHz band (1.25 MBaud), plus Galileo and FPGAs, codecs and discrete analog components.
CO	Central Office. Of a local exchange carrier, the local "phone company".
COFDM	Coded Orthogonal Frequency Division Multiplexing
Codec	Coder and Decoder. In hardware, the chips that convert analog to digital samples and convert digital samples to analog.
CRA	Collision Resolution Algorithm
CRC	Cyclic Redundancy Check
Crop	Clipping, or removing parts of video that are not displayed.
CSM	Chartered Semiconductor Manufacturing.
CSMA/CD	Carrier Sense Multiple Access with Collision Detection. Ethernet Media Access Control algorithm.
CSS	Content Scrambler System. Encryption scheme for DVD. Also Cascading Style Sheet (HTML).
CWDM	Coarse Wave Division Multiplexing.
DAC	Digital-to-Analog Converter
D1	Uncompressed Digital Video and Audio standard used to master movies. Resolution is 480 lines by 720 pixels.
DA	Destination Address
DAC	Digital to Analog Converter
Dark Fiber	Unused fiber optic cable, sometimes referred to as "unlit glass."
DASE	Digital TV Application Software Environment
DAVIC	Digital Audio Visual Council
DBC	Data-parallel bit-serial C
DBS	Digital Broadcast Satellite. A broadband communications technology that broadcasts digital television programming from satellites directly to dish antennas.
DCT	Discrete Cosine Transform. A technique for compressing images by converting them into the frequency domain. Used in JPEG, MPEG, and H.261.
Digital Broadcasting	Digital terrestrial television over-the-air broadcasting using CDV.
DCOM	Distributed Component Object Model. Microsoft COM follow-on.
DDK	Device Driver Kit. Some DDK's are OS-specific (Windows 95, NT 4.0, NT 5.0, 98, CE) others are device class-specific.
DDFS	Dynamic Device File System. DDFS is an architecture which requires a driver to support a combination of a particular host adapter and a particular storage device or set of devices.
DDS	Digital Data Source, Digital Data System, Dataphone Digital Service.
DECT	Digital Enhaced Cordless Cordless Telecommunication. Phone standard used in SWAP.
DFE	Decision Feedback Equalizer. Digital signal processing technique to determine equalization based on previous symbol sequence.
DFPQ	Distributed Fair Priority Queuing. Collision resolution algorithm.
DHTML	Dynamic HyperText Markup Language.
Digital Difference	The subtraction of two "signals" (numbers, images, etc.) in the digital domain.
DirectDraw	Part of DirectX for video rendering.
DLC	Digital Loop Carrier. Combines several local loops into a single T1 line.
DMIF	Delivery Multimedia Integration Framework. MPEG-4 effort for combined audio, video, web pages, and kitchen sinks, over 28 Kbps modems.
DMT	Discrete MultiTone.  The official T1.413 standard modulation scheme for Digital Subscriber Line technology (xDSL) patented by Amati (now TI).
DNA	Distributed interNet Applications
DNS	Domain Name Services. Uses name rather than an actual Internet Protocol(IP) address for simplicity.
Dolby	Company that does many quality audio encodings.
DOM	Document Object Model, web page standard from W3C.
Downstream	Data flowing from the central office (CO) to the subscriber. In technolgies like ADSL the downstream data rate is significantly higher than upstream
DRC	Design Rule Check. Performed on a chip before being manufactured.
DSLAM	Digital Subscriber Line Access Module
DS0	Digital Service level zero. Same as BRI,  Equivalent to one telephone call's worth of bandwidth.
DSP	Digital Signal Processing
DS1	Digital Service level one. 1.554 Mbps, which can carry 24 telephone calls. A Physical interface that carries this service is called T1.
DS3	Digital Service level three. About 45 Mbps, or 30 DS1 channels.
DSLAM	Digital Subscriber  Line Access Multiplexer. Concentrates up to hundreds of xDSL subscribers onto a smaller number of ATM trunk lines.
DSS	Digital Satellite System
DSP	Digital Signal Processing. A signal processing technique that takes real-time, high-speed signals, such as radio, cellular phones, or satellite TV broadcasts, then mathematically alters it to improve the signal. This technology includes filtering, speech recognition, image enhancement, data compression, and noise reduction.
DSPPhy	Coding and decoding data with a Digital Signal Processing chip.
DST	Destination
DSTS	Desktop Support Tracking System
DTLA	Digital Transmission Licensing Authority organization for DTCP.
DTCP	Digital Transmission Content Protection (for 1394).
DTS	Digital Theater System. Audio quality competes with Dolby Digital AC-3.
DTV	Digital Television, includes HDTV and digital versions of SDTV.
DV	Digital Video. Generic term, and a specific DCT protocol for 1394 camcorders.
DVD	Digital Versatile Disc, sometimes Digital Video Disk. Follow-on to CD-ROM, nominal 9 Mbps transfer rate.
D-VHS	A Digital Video format promoted by JVC. Designed to record Digital Broacast Satellite (DISH) programs and play older VHS tapes.
DVI	Digital Video Interactive. A package of technology from Intel, including some popular compression formats.
DWDM	Dense Wavelength Division Multiplexing
DWM	Dense Wavelength Division Multiplexing
E-Commerce	Electronic Commerce. Electronic transactions between business and customers via the Internet.
EBI	External Bus Interface
ECL	Emitter Coupled Logic
Electronic Media Distribution	A method of distributing electronic media, usually as a download over the Internet.
Enhanced Digital Broadcast	Enhanced Digital Broadcast combines the storytelling of television with the interactivity of the Web.
ENIC	Board with discrete Analog Front End plus digital chip.
EOF	End Of File, or End Of Frame.
EPAC	Extended Perceptual Audio Coder. With CD quality at 128 Kbps.
EPIC	Electronic Privacy Information Center
Epidiag	TCL front end to simple diagnostics driver.
Epindd	NIC Diagnostic Driver for Epidiag.
Ethernet (10BASE-T)	Networking protocol widely used in local area networks (LANs) for connecting devices by means of copper twisted-pair wiring at speeds of 10 Mbps.
FA	Functional Array
Fast Ethernet (100BASE-T)	An extension to the 10BASE-T Ethernet network access method, Fast Ethernet operates at 100 Mbps.
FCC	Federal Communications Commision
FDQAM	Frequency Diverse Quadrature Amplitude Modulation
FDM	Frequency Division Multiplexing
FEC	Forward Error Correction. A receiver technique for correcting errors in the received data.
FIB	Focused Ion Beam. Process of making changes to an integrated circuit after fabrication.
Fiber Channel	A high-speed data link planned to run up to 2 Gbps on a fiver optic cable.
Fiber Optics	A method of data transmission in which data is modulated on to light and is transmitted at very broad bandwith fibers over very pure, extremely thin glass fibers.
Fiber-Optic Cable	A cable made of glass fibers that transports data or voice signals.
Filtering	A process used in both analog and digital processing to pass one frequency or frequency band while blocking others or visa versa.
FIR	Finite Impulse Response. A very useful kind of digital filter.
FireWire	Apple name of what is now the IEEE P1394 standard.
Flow	A sequence of packets that share enough common characteristics (such as source and destination) that they can be routed the same way, and handled with the same quality of service policy.
FFE	Feed Forward Equalization
FIFO	First In, First Out
FourCC	Four Character Codes for video pixel formats.
FPBGA	Fine Pitch Ball Grid Array
FPGA	Field Programmable Gate Array. Quick way to make low volume integrated circuits.
FR	Frame Relay. A common service used to connect LANs.
Frame	Unit of data sent between the data link layer and Frame Relay.
FSK	Frequency Shift Keying
FSE	Fractionally Spaced Equalizer
FUNI	Frame User Network Interface. A service on ATM using frames instead of bit streams.
G.dmt	A Proposed xDSL standard using discrete multi tone modulation.
G.hs	AA proposed xDSL standard for negotiation to decide which of all the different versions are being used on a particular line.
G.lite	The ADSL Forum supports the UAWG's mission to create a universal, splitterless, and therefore easy to install lower-speed version of ADSL (G.lite or DSL-lite).
GA	Grand Alliance. 18 digital (including HDTV) standards.
GMIC	Glass Microwave Integrated Circuit
GMII	Gigabit Media Independent Interface
Gps	Giga bits per second. 1,000,000,000 (one billion) bits per second, a measure of telecommunciatons speed.
GCC	The GNU C compiler.
GDB	The Gnu DeBugger.
Genlock	Synchronizing multiple video sources to the same clock.
GHz	Giga Hertz. One billion cycles per second.
Gigabit Ethernet (1000BASE-T)	An extension to the 100BASE-T Ethernet network access method which operates at 1,000 Mbps or equivalently 1 Gbps.
Gigabit PHY	Gigabit PHY is the specific description for a PHY operating at 1000Mbps
G.Lite	The new ITU standard that forms the basis of Universal ADSL, which supports 1.5 Mbps downstream and 384 Kbps upstream.
GPIC	GNU version of pic, which is part of the groff document formatting system. pic compiles descriptions of pictures embedded within troff or TeX input files into commands that are understood by TeX or troff.
GSM	Global System for Mobile phones.
H.261	A common simple video compression technique, originally used for video conferencing.
HAVi	Home Audio Video interoperability. A standard for 1394 (Firewire) devices.
HD0	Digital television "standards", this one favored by Microsoft. Still only 480 lines, but 60 progressive frames instead of interlaced.
Headend	In a local area network, a device that receives signals from each data station and then retransmits the signals to all the data stations.
HDSL	High Data Rate Digital Subscriber Line. This DSL variety created in the late 1980's delivers symmetric service at speeds up to 2.3 Mbps in both directions.
HDTV	High Definition Television. Offers six times the resolution of current TV and a full 60 frames per second temporal resolution which is twice the vertical and horizontal resolution of current NTSC analog television broadcasting. It also supports near-CD (compact disc) sound quality.
Headend	The central distribution point in a cable television system. Typically serves tens to hundreds of thousands of homes.
HFC	Hybrid Fiber Coax. Upgraded cable plant which uses a combination of fiber optic cable in the backbone and coaxial cable in the subscriber feeder plant.
HMAC	Hashed Message Authentication Code
HPNA	Home Phoneline Network Alliance
HSSI	High Speed Serial Interface (port)
HTML	HyperText Markup Language. The authoring language used to create documents on the World Wide Web.
IAT	Inter-Arrival Time
IC	Integrated Circuit
idbg	Interactive Debugger
IEEE 802	Local Area Network standards family, wildly successful. Ethernet is effectively one of them.
IETF	Internet Engineering Task Force
IFG	Inter Frame Gap. Minimum spacing between frames called IPG in 802.
IFMP	Flow Management Protocol. Allows a host to instruct an adjacent node (e.g. an Ipsilon switch controller) to attach a network layer label to a flow, so subsequent packets on that flow can be switched in hardware.
ILEC	Incumbent Local Exchange Carrier. The traditional phone company.
INIC	Integrated Network Interface Card. Yet another NIC with custom analog and digital chips on it.
INICT	INIC board with extra testing features.
Interlaced	Even Lines in one video field, then odd lines, opposite of progressive.
Intserv	The IETF working group on Integrated Services. That is, real time traffic such as audio and video over the Internet.
IOCTL	Input Output Control
IP	Internet Protocol
IPG	InterPacket Gap
IRP	Input/output Request Packet
IRQ	Interrupt ReQuest
ISA	PC bus (before PCI).
ISDN	Integrated Service Digital Network
ISO	International Standards organization
ISP	Internet Service Provider. A company that provides a subscriber a connection to the Internet.
ISSLL	Integrated Services over Specific Lower Layers
ITU	International Telecommunications Union. The world telephone standards body.
Java	Sun programming language
JMF	Java Media Framework
JPEG	Joint Picture Experts Group. Usually refers to a DCT image compression standard.
JTAG	Joint Test Action Group, (IEEE Standard 1149.1). Common connector for testing.
Judder	Temporal aliasing artifact of digital video processing. For example, displaying a 30 frames per second image on a 75 Hz PC monitor.
JVM	Java Virtual Machine
k56flex	A 56 Kbps modem technology developed by Rockwell and Lucent.
Kbps	Kilobits per second. Kilo usually means one thousand. Also written as Kbits/sec or Kb/sec.
KS	Kernel Streaming interface in Windows Driver Model for video, audio, etc...
L2TP	Layer 2 Tunnel Protocol. Runs the PPP protocol over IP for virtual private nets.
LACP	Link Aggregation Control Protocol
LAN	Local Area Network. A private data communications network linking a variety of data devices such as computers and printers within an office or home environment.
LANE	LAN Emulation. ATM service for Ethernet bridging.
LE	Linear Equalization
LFSR	Linear Feedback Shift Register
LeapFrog	A VHDL simulator.
LEC	Local Exchange Carrier. The local phone company.
Line 21	Closed captioning standard (displays text at the bottom of video).
LLC	Logical Link Control
LMDS	Local Multipoint Distribution System. A broadband wireless communications network that uses microwave frequencies around 28 GHz to transmit video and data to residences over a cellular-like network at distances under a few miles.
Loop	The single pair for wires running from the central office (CO) to each telephone.
LPF	Low Pass Filter
lsb	least significant bit
LVS	Layout versus Schematic
MAC	Media Access Control. Protocol for controlling the upstream and downstream traffic flow in a local or wide area network.
Macrovision	Analog scheme that discourages making copies of video content on VHS tapes.
MBone	Multicast Backbone
Mbps	Megabits per second. One million bits, and not 1024 times 1024. Also written as Mbits/sec or Mb/sec.
MCI	Media Control Interface
MD5	Message Digest 5. This is a hash algorithm.
MCNS/DOCSIS	Multimedia Cable Network System / Data Over Cable Service Interface Specification. Industry specification that defines the technical equipment for high-speed cable modem and headend equipment.
MDI	Multiple Document Interface, Media Dependent Interface.
MDIX	Media Dependent Interface Crossover
Media Appliances	Consumer electronics devices that feature digital functions, combining the power of the PC with the convenience of traditional consumer devices.
MER	Modulation Error Rate
MGCP	Media Gateway Control Protocol
MIB	Management Information Base. The specification of SNMP object numbers for one specific kind of management agent. The basic IP MIB is often called MIB-II.
MII	Media Independent Interface
Modem	MODulator/DEModulator. Conventional modems comprise equipment which convert digital signals to analog signals and vice versa.
MQFP	Medium Quad Flat Pack
MII	Media Independent Interface. Replaces 10Base-T Ethernet's Unit Interface (AUI), and is used to connect the MAC layer to the physical layer. The MII establishes a single interface for 100Base-TX, 100Base-T4, and 100Base-FX.
MIME	Multimedia Internet Mail Extension
MIPS	Microprocessor without Interlocked Pipelined Stages.
MMDS	Multichannel Multipoint Distribution Service. A broadband wireless communications network that uses microwave frequencies around 2.5 GHz to transmit video to residences at distances up to tens of miles.
Modem	Modulator and Demodulator. Converts between digital data and an analog channel (such as a telephone line).
MP3	MPEG level 3 audio. Can be used with MPEG-1 or 2 video, or by itself.
MPEG	Moving Pictures Experts Group. Industry standard for compressing and decompressing digital audio video signals.
MPLS	Multi Protocol Label Switching. IETF technique for large point-to-point networks.
MSAD	Modern Systems Analysis and Design
MSB	most significant bit
MSE	Mean Squared Error
MSI	Microprocessor Slave Interface
Multiplexer	An electronic device that allows multiple channels to be combined into a single signal.
MUSE	Japanese analog HDTV standard, as opposed to digital ATSC.
NAT	Network Address Translation. Mapping IP addresses across a gateway to avoid allocating a real block of address space.
NCC	Networking Communications Conference
NCPA	Network Control Panel Applet
NDD	NIC Diagnostic Driver, (replaced by EpiNDD).
NESL	Netware Event Service Layer
NDIS	Network Driver Interface Specification. Version 4.0 in Windows 95 OSR2, 4.1 in NT 4.0, version 5.0 in Windows 98 and NT 5.
NEBS	Network Equipment Building System
NEXT	Near End Cross Talk. A problem with modems over bad wires.
NGIO	Next Generation Input and Output
NIC	Network Interface Card. Plug-in adapter card enables a computer to connect to a LAN.
NID	Network Interface Device. Box between phone line and premise network.
NLE	Non-Linear Editing of video, as opposed to tape.
NPN	Negative Positive Negative
NSR	NIC Sample Recorder
NTSC	Never Twice the Same Color. The US Analog Television standard.
OAM	Operations, Administration, and Maintenance
OC-3	Optical Carrier level three
OC-12	Optical Carrier level twelve. An ATM rate at about 622Mbps.
OFDM	Orthogonal Frequency Division Multiplexing. Used in European digital television system.
OHCI	Open Host Computer Interconnect. Between IEEE 1394 and a computer.
OID	Number space used in NDIS set and get information calls.
OLE	Object Linking and Embedding
Orca	Optimized Reconfigurable Cell Array
OVS	Open Video System. Scheme to send digital video without proprietary encapsulations (such as DSS).
Packet	A variable-sized unit of information that can be sent across a packet-switched network. NTSC.
PAL	Phase Alteration Line. 50 Hz video format used in much of the world outside of the USA. Not NTSC.
PAR	Peak to Average Ratio. Also, Project Authorization Request. When IEEE starts a new standards committee.
PCI	Personal Computer Interface. The bus that most personal computers use.
PCM	Pulse Code Modulation. A common lossless encoding of Audio.
PDU	Protocol Data Unit. Usually ISO speak for "packet".
PE	Protocol Engine. The general purpose programming engines of our defunct switch.
PHY	Physical Layer Device. A PHY can be a fiber optic device or a copper device. It can operate at any speed... 1Mbps, 10Mbps, 100Mbps, 1000Mbps, etc.
PMMU	Paged Memory Management Unit
PNP	Positive Negative Positive
POF	Plastic Optical Fiber
Point-to-Multipoint	An arrangement, either permanent or temporary, in which the same data flows or is transferred from a single origin to multiple destinations.
POP	Point Of Presence
Port	A specific line into a switch, specified by shelf, slot, and port within that slot.
POST	Power On Self Test
POTS	The traditional analog voice telephone service (4 kHz or less audible signals, rings, off hook signals, etc...).
PPP	Point to Point Protocol. Some standard encapsulations and negotiations for Internet Protocol point-to-point links.
PPTP	Point to Point Tunnel Protocol
PQFP	Plastic Quad Flat Pack
PR	Public Relations, Press Relations, or Press Releases.
PRM	Preamble. Header on each frame used to train demodulator.
PSD	Power Spectral Density
PSK	Phase Shift Keying. Modulation with constant amplitude.
PSTN	Public Switched Telephone Network
PThread	POSIX Thread. A "standard" multi-tasking OS primitive interface.
PVC	Permanent Virtual Connection. A manually configured virtual circuit through an ATM network.
QAM	Quadrature Amplitude Modulation. A digital modulation technique that allows very efficient transmission of data over media with limited available bandwidth.
Quick Turn	The purchase and sale of an investment held for only a very brief period of time, such as in day trading.
QPSK	Quadrature Phase Shift Keying. A digital technique which is widely employed in direct broadcast satellite transmission systems.
QSIF	Quarter Standard Interchange Format.
RADIUS	Remote Authentication Dial-In User Service. Authorization protocol, IETF RFC  2138
RADSL	Rate Adaptive Digital Subscriber Line. Picks the best data rate that the line can handle.
RDT	Remote Digital Terminal
RED	Random Early Drop. A congestion control algorithm for Internet protocols.
RGB	Red Green Blue. Component video color model used in PC frame buffers, and high end professional (even digital) systems.
relite	Integrated analog front end for DNIC.
Repeater	Device that amplifies weak signals without regeneration or processing.
RF	Radio Frequency
RFC	Request For Comments. Traditional name for Internet standards documents (and Internet informational documents).
RFP	Request for Proposal
RLL25	Run-Length Limit bit encoding used in Tut HomeRun.
RMAN	Resource Manager. Part of the switch software.
RMII	Reduced Media Independent Interface
RMS	Root Mean Square. An "average" of an analog signal.
Router	A device that routes data between networks through IP addressing information contained in the header of the IP packet.
RPC	Remote Procedure Call
RSVP	Resource Reservation Protocol
RTR	Runtime Reconfigurable (system)
RTS	Run Time Support.
SA	Source Address
SAN	System Area Network. Now, Storage Area Network (disks and tapes).
SAP	Session Announcement Protocol
SBUS	A proprietary input/output (I/O) bus developed by Sun Microsystems
SCLK	Synchronous with Clock
SCRAMBLER	In 1000BASE-T and 100BASE-TX modes, the transmit data stream is scrambled to reduce radiated emissions and to ensure that there is no correlation between symbols in the data stream.
SDH	Synchronous Digital Hierarchy. CCITT Family of data networking standards for high rates over fiber-optics.
SDI	Serial Digital Interface, for video uncompressed, e.g. 1.5 Gbps for HDTV.
SDP	Session Description Protocol. Used in IETF protocols to announce multimedia events, through the session announcement protocol, SAP.
SDSL	Symmetric Digital Subscriber Line. A flavor of xDSL with the same bandwidth in both directions.
SDTV	Standard Definition Television, 480 lines or less.directions.
Server Farm	A system that allows for scalable, fault-tolerant, and centralized connectivity for enterprise servers.
Set-top Box	An electronic device that serves as an interface between a television set and a broadband network.
SHA-1	Secure Hash Algorithm
SIC	System area network Interface Chip
SKU	Stock Keeping Unit
SLB	Smart Load Balancing
SLI	Subscriber Line Interface (telephone)
SLIC	Subscriber Line Integrated Circuit, System Level Integrated Circuit, Subscriber Line Interface Card.
SMB	Send Message Block. Microsoft file access protocol.
SMII	Serial Media Independent Interface
SMDS	Switched Multimegabit Data Service
SMIL	Synchronized Multimedia Integration Language
SNAP	Sub Net Access Protocol. Header on LLC frames so that the alignment comes out a little better, with three bytes of zeros, then the Ethernet type identifier for the network level protocol 0x08 and 0x00.
SNMP	Simple Network Management Protocol. Used to manage IP networks, by defining standard MIBs.
SNR	Signal to Noise Ratio
SOHO	Small Office, Home Office
SONET	Synchronous Optical NETwork. A common physical layer for ATM using fiber optics. Also possible to run PPP or other protocols on top of it. American variant of SDH. Organized into rings that can tolerate one break (e.g. FDDI).
SPI	Serial Plug In, Standard Programming Interface, Spots per Inch.
SRC	Source (e.g. address of a packet).
SRX	Serial Receive Line
STB	Set Top Box (such as for cable TV).
Streaming Media	Multimedia content - such as video, audio, text, or animation that is displayed by a user as it is received from the Internet, broadcast network, or local storage.
STX	Serial Transmit
Sub-ISA	Subset of ISA bus used by the iLine10 chip to bridge to some other device (such as modem).
Symbol Rate	Replacement term for Baud: a unit of signaling speed, the number of times a signal on a communications circuit changes.
SVC	Switched Virtual Connection
SWAP	Shared Wireless Access Protocol developed by HomeRF.
T	Thin
T1	A DS1 rate (1.544 Mbps) signal delivered on two twisted pair of copper wires. The closest European equivalent is called E1, which is 2.048 Mbps. Also a committee of ANSI that does telecommunications standards.
TAG	Temporal Annotation Generator. Audio/video editor licensed from Digital Renaissance for NetShow.
TAPI	Telephony Application Programmers' Interface
TBI	Ten Bit Interface
TCL	Tool Command Language
TCP	Transmission Control Protocol
TDM	Time Division Multiplexing
TDMA	Time Division Multiple Access
Telecine	Converting movies (24 frames per second) to video (usually 30 frames per second).
TIC	Time Interval Clock. Tut for 116.6667 nsec.
TMN	Telecommunications Management Network
TOEF	Training on Every Frame. A true packet modem using only the frame preamble.
TOS	Type Of Service
TQFP	Thin Quad Flat Pack
Transceiver	NIC MIPS program which performs energy detection and transfers samples to and from the AFE.
Trunk Card	Card to connect the switch to an Internet Service Provider (ISP).
Twisted Pair	Cable of two 18 to 24 guage solid copper strands twisted around each other.
TQFP	Thin Quad Flat Pack. Package of first iLine10 digital chip.
Tuner	Any device or apparatus used for selecting and controlling the operating frequency of a circuit or equipment, such as the channel selector in a television receiver.
UART	Universal Asynchronous Receiver/Transmitter
UAWG	Universal ADSL Working Group
UNC	Uniform Naming Convention
UNI	User to Network Interface. Protocol between an ATM carrier and a customer.
Upstream	Data flowing from a subscriber towards the central office (CO). Some old Video on Demand terminology calls this "duplex", as compared to traditional cable TV witch is simplex (one direction, downstream, only).
USB	Universal Serial Bus. On every PC since 1997, allows peripherals (albeit sometimes called dongles) to be added without taking a box apart. ~12 Mbps.
UTP	Unshielded Twisted Pair
VCO	Virtual Central Office. The Cisco VCO/4K (Virtual Central Office 4000) is a programmable switch that provides voice services such as integrated messaging, operates as a core infrastructure switch for wireline or wireless networks, or acts as a gateway in mixed circuit- and packet-switched networks.
VSB	Vestigial Side Band. One of the Digital Television modulations.
V.34	Most common modem modulation. 28.8 Kbps rate.
V.90	Standard for 56 Kbps modems, merging k56flex and x2.
V.anything	Implement modem algorithms in software.
V.IP	Residential Ethernet The internal name V.IP is a pun on the V.n series of modem standards.
VBI	Vertical Blanking Interval
VBR	Variable Bit Rate.
VCC	Virtual Channel Connection. Identifies a virtual circuit in an ATM switch through an input port, a virtual channel identifier and virtual path identifier.
VCI	Virtual Circuit Identifier. Part of ATM VCC. 16 bits specifying a connection on a particular path.
Vector OFDM	Vector Orthogonal Frequency Division Multiplexing.
VDSI	Very High Delivered Source Instruction
VDSL	Very High Bit-Rate Digital Subscriber Line. Twisted pair modem technology that achieves data rates up to 52 Mbps downstream to the network at distances up to 4,000 feet.
VESA	Video Electronics Standards Association. Consumer electronics inter-connection.
VHDL	Verilog Hardware Description Language
VHE	Virtual Home Environment. GSM scheme to allow cellular phones to work when you leave one provider area and go to another.
VISA	Virtual Instrument Standard Architecture
Viterbi	Algorithm for BCC Forward Error Correction.
VOB	Video OBject. File format for DVD-video.
VOFDM	Breakthrough radio frequency(RF) thechnology developed to establish an open broadband fixed wireless standard for enabling reliable communicaion where line of sight connections are not practical.
VPC	Virtual Path Connection
VPE	Video Port Extension
VPI	Video Port Extension or Virtual Path Identifier.
VSB	Vestigial Side Band. Modulation used for broadcast digital telelvision.
VxWorks	An operating system for embedded devices.
WAN	Wide Area Network. A data communications network, such as the Internet, which links a variety of data devices over a large geographical distance.
Wavelet	Wavelets are mathematical functions that cut up data into different frequency components, and then study each component with a resolution matched to its scale.
WFC	Windows Foundation Classes. Microsoft Java package.
WFQ	Weighted Fair Queuing
Whiff	Operating system running on Digital Signal Processors.
WHQL	Windows Hardware Quality Laboratory
Win32	Important API for Windows 3.x, 95, etc.
WinCE	A variant of Microsoft Windows for palm tops and embedded applications.
Wind	The VxWorks kernel.
WinPHY	Coding and decoding in software by WinModem.
Winsock	Microsoft network programming interface.
Wire Center	The other end of the local loop wires from subscribers.
WMI	Windows Management Instrumentation in NT 5 and Windows 98.
WMP	Window Media Player
x2	A modem technology from U.S. Robotics to send 56 Kbps over voice phone lines.
xDSL	Generic representation of the entire family of Digital Subscriber Line technology spanning data rates from 128 kbps to 52 Mbps depending on the distance between the central office subscriber.
XML	Extensible Markup Language
xNIC	A "D" Network Interface Card with Xilinx FPGAs, in 4-10 MHz band.
Y/C	Video signal with separate luminance and chrominance signals, which often is used on S-Video connectors.
YCrCb	A color model for video.
YUV	A color model for video. The popular 4:2:2 encoding means Y (Luminance) is sampled twice as often as the UV color values.
YUV12	A specific digital video pixel format. A plane of 8 bit Y values per pixel, then a plane of 8 bits of U values per four pixels, and 8 bits of V per four pixels. This gives an average of 12 bits of data per pixel.
YUV9	Like YUV12, but with 4:1:1 sampling, one color value for 16 pixels, for 9 bits per pixel average.