56Flex-

56Flex-@

56Flex

See K56flex.

5B6B

5 Bits 6 Bits. A data encoding/decoding scheme that encodes five data bits into a 6-bit transmission sequence. 5B6B is used in 100VG-AnyLAN, which is standardized as IEEE 802.12, and which supports both Ethernet and Token Ring LANs. With 5B6B, the data frames to be transmitted over the serial (i.e., one bit at a time) link are divided into 5-bit data quintets. Each quintet is then scrambled, using a different scrambling mechanism for each of the four channels (i.e., wire pairs) in order to randomize the bit patterns on each channel and, thereby, to reduce radio frequency interference (RFI) and the resulting crosstalk between the pairs. At that point, the each quintet is encoded, or mapped, into a predetermined 6-bit "symbol," which process creates a balanced data pattern comprising equal numbers of 1's and 0's. The expanded symbol (five bits become six bits) provides both clock synchronization between transmitter and receiver, and error-detection capability. As there exist only 16 balanced 5-bit symbols (i.e., data patterns) available, and as there exist 32 unique five-bit data combinations (Note: 2 to the fifth power equals 32.), 16 of the data quintets require expression in the form of two 6-bit symbols. The pattern of one and two 6-bit symbols is used alternately to maintain DC balance. Then, each symbol is prepended with a preamble and starting delimiter, and is appended with an ending delimiter . Finally, and in a process known as "quartet channeling ," the quintets are distributed sequentially over each of the four channels, with each channel being in the form of a wire pair in a four-pair configuration. This channel definition is based on the " lowest common denominator" assumption that Cat 3, 4, or 5 UTP ( Unshielded Twisted Pair) is used for connectivity between the workstation and the hub. If either 2 pairs of STP ( Shielded Twisted Pair) or two optical fibers (of 62.5 microns) are used, the 6-bit symbols are multiplexed before being transmitted. See also 5B6B, 8B6T, 8B10B and 100VG-AnyLAN.

5ESS

A digital central office (also called a public exchange) switching system made by Lucent. It is typically used as an "end-office," serving local subscribers. But it is also used by some GSM cellular operators as transit switches connecting their MSCs (mobile switching centers).

5x5

See Five By Five.

5XB

5 X-Bar central office equipment.

611

Phone number used by many carriers (including cell phone providers) in North America for telephone company repair service. You dial it to report problems or ask service- related questions. See also N11.

613

Mitzvah in Jewish can be literally translated as a commandment. Mitzvot is the plural form for Mitzvah and it means the 613 commandments, including the first ten, which are more well known as The Ten Commandments .

62

Sixty-two degrees Fahrenheit is the minimum temperature required for a grasshopper to be able to hop.

64 bit architecture

A 32-bit processor can handle up to 4 billion bytes of memory, an amount rarely approached in ordinary desktop computing today. By comparison, a 64-bit chip can address 18 billion bytes.

66 Block

The most common type of connecting block used to terminate and cross-connect twisted-pair cables. It was invented by Western Electric eons ago and has stood the test of time. It's still being installed. Its main claims to fame: Simplicity, speed, economy of space. You don't need to strip your cable of its plastic insulation covering. You simply lay each single conductor down inside the 66 block's two metal teeth and punch the conductor down with a special tool, called a punch-down tool. As you punch it down, the cable descends between the two metal teeth, which remove its plastic insulation (it's called insulation displacement) and the cable is cut. The installation is then neat and secure. 66 blocks are typically rated Category 3 and as such are used mostly for voice applications, although Category 5 66 blocks are available. 66 blocks are open plastic troughs with four pins across, and the conductors tend to be more susceptible to being snagged or pulled than the conductors terminated on 110, Krone or BIX. Why is it called 66 block? According to AT&T, all these things were developed and named by Bell Labs. They just started with "number 1" on whatever system they were working on. TD1 radio, TD2 radio, etc. Whenever there was a "hole" in the sequence, that meant that the labs had worked on something, but it didn't pan out for some reason. I guess 1 through 5 didn't pan out.

64 Kbps

64,000 bits per second. The standard speed for V.35 interface, DDS service, and also the effective top speed of a robbed-bit 64 Kbps channel. A 64 Kbps circuit (DSO). "Clear Channel" is 64 kbps where entire bandwidth is used. See also ISDN.

64-bit

See 64 bit.

64-cap

An ATM term . Carrierless Amplitude/Phase Modulation with 64 constellation points.

64QAM

64-state quadrature amplitude modulation. This digital frequency modulation technique is primarily used for sending data downstream over a coaxial cable network. 64QAM is very efficient, supporting up to 28-Mbps peak transfer rates over a single 6-MHz channel. But 64QAM's susceptibility to interfering signals makes it poorly-suited to noisy upstream transmissions (from the cable subscriber to the Internet). See also QPSK, DQPSK, CDMA, S-CDMA, BPSK and VSB.

66-type Connecting Block

A type of connecting block used to terminate twisted-pair cables. All wires are manually cut down with a special tool to terminate or connect them. See 66 Block.

66-type Cross Connect

A cross connect made up of the 66-type connecting blocks and jumper wires for administering circuits. All wires, including jumper wires, must be cut down (or punched down) and seated with a special tool. See 66 BLOCK.

6611

IBM's multi-protocol router, which supports APPN in addition to TCP/IP, DECnet, AppleTalk, IPX, NetBIOS, and other protocols.

6bone

The Internet's experimental IPv6 network. 6bone is an informal collaborative project designed as a testbed backbone network for IPv6 (Internet Protocol version 6), commonly known as IPng (Internet Protocol next generation). The 6bone is a virtual network layered on top of portions of the IPv4-based Internet. In the core of the 6bone are production-level (versus beta test-level versions) routers running the IPv6 protocol suite, connected to workstation-class machines also running native IPv6. The islands of IPv6 are connected to the current IPv4-based Internet through edge routers running both the IPv4 and IPv6 protocol suites. The plan is that, over time, IPv6 will gradually work its way throughout the Internet, replacing IPv4 in the process. See also IPng, IPv4, and IPv6.

7-bit ASCII

The standard code for text in which a byte (eight bits) holds the seven ASCII digits that define the character plus one bit for parity.

700 Service

A non-geographic area code reserved for the provisioning of special IXC services, 700 numbers were created in 1983, with the intent that interexchange carriers could use them to create and implement new services quickly. AT&T originally marketed 700 Service in the form of Easyreach, which allows your calls to follow you in the same fashion as would 500 Service. Some carriers (who will remain unnamed) once used 700 numbers for user access to the network for purposes of intraLATA long distance calling, such as those from Manhattan to Westchester County ” the cost presumably was less than the cost of the same call through the serving LEC. This practice was illegal and no longer is necessary, as local competition now is in place in most states. 700 Service is still evolving, with each carrier having the right to create whatever services it wants with its 700 numbers. Currently, 700 Service commonly is used in both voice and data VPNs (Virtual Private Networks). See also 500 Service and VPN.

701

The 701 was one of the first manual switchboards , also called a cordboard. it was made by Western Electric. A manual switchboard required the operator to insert a cord into the slot on a board that represented the location of a department or person receiving a call.

IBM's first computer, introduced in 1953. It was also known as the Defense Calculator.

709.1

EIA/ANSI 709.1 is an open, device networking and control communications protocol. In most fields, it's known as the LonWorks Platform. It's designed to connect all manner of devices to the Internet ” from electricity meters to subway doors. See also www.Echelon.

711

The Services Code now available for Telecommunications Relay Access (TRS) to aid those with speech and/or hearing disabilities to access police, fire and other governmental departments for both emergency and non-emergency purposes. See also 911 and 311.

8.3

Under the MS-DOS naming structure, a file's name can be eight letters in front of the period and three after it, e.g. LAZARUS8.TXT.

8.3 minutes. The time it takes for light to travel from the Sun to the Earth.

8-bit Computer

A computer that uses a central processing unit (CPU) with an 8- bit data bus and that processes one byte (8 bits) of information at a time. The first microprocessors used in personal computers, such as the MOS Technology 6502, Intel 8080, and Zilog Z-80, were installed in 8-bit computers such as the Apple II, the MSAI 8080, and the Commodore 64.

800

The first "area code" for what AT&T originally called In-WATS service. See 800 Service and 8NN.

800 Portability

800 Portability refers to the fact that you can take your 800 number to any long distance carrier. A case example, once I had 1-800-LIBRARY. For many years , that number was provieded by AT&T. When portability came along, we were able to change it from AT&T to MCI and still keep 1-800-LIBRARY, which is 800-542-7279. 800 Portability is provided by a series of complex databases the local phone companies, under FCC mandate , have built. 800 Portability started on May 1, 1993. See 800 Service.

800 Service

A toll free call paid for by the called party, rather than the calling party. A generic and common term for In-WATS (Wide Area Telecommunications Service) service provided by a phone company, whether a LEC (Local Exchange Carrier) or an IXC (IntereXchange Carrier). In North America and in order of their introduction, all these In-WATS services have 800 (1967), 888 (1996), 877 (1998), 866 (2000), or 855 (2001) as their "area code." (Note: Future 800 numbers will follow the convention 8NN, where NN are specific numbers which are identical. Such 800 service is typically used by merchants offering to sell something such as hotel reservations , clothes, or rental cars . The idea of the free service is to entice customers to call the number, with the theory being that if the call was a toll call and therefore cost the customer something, he or she might be less inclined to call. Suppliers of 800 services use various ways to configure and bill their 800 services.

800 Service works like this: You're somewhere in North America. You dial 1-800, 1- 888, 1-877, 1-866 or 1-855 and seven digits. The LEC (Local Exchange Carrier, i.e., the local phone company) central office sees the "1" and recognizes the call as long distance. It also recognizes the 8NN area code and queries a centralized database before processing the call further, with the query generally taking place over a SS7 (Signaling System 7) link. The centralized database resides on a Service Management System (SMS), which is a centralized computing platform. The database identifies the LEC or IXC (InterExchange Carrier) providing the 8NN number. Based on that information, and assuming that the toll- free number is associated with an IXC, the LEC switch routes the call to the proper IXC. Once the IXC has been handed the call, it processes the 800 number, perhaps translating it into a "real" telephone number in order to route it correctly. Alternatively, the IXC translates the 800 number into an internal, nonstandard 10-digit number for further routing to the terminating Central Office (CO) and trunk or trunk group .

As a real-life example, the publisher of this book has an 800 number, 800-LIBRARY (or 800-542-7279). When you call that number, MCI routes that number to the first available channel on the dedicated T-1 circuit which leased from MCI's, and connecting the MCI New York City POP (Point Of Presence) to the CMP New York City office.

Because 800 long distance service is essentially a database lookup and translation service for incoming phone calls, there are endless "800 services" you can create. You can put permanent instructions into the company to change the routing patterns based on time of day, day of week, number called, number calling. Some long distance companies allow you to change your routing instructions from one minute to another. For example, you might have two call centers into which 800 phone calls are pouring. When one gets busy, you may tell your long distance company to route all the 800 inbound phone calls to the call center, which isn't busy. See Eight Hundred Service and One Number Calling for more, especially all the features you can now get on 800 service.

In May of 1993 the FCC mandated that all 800 (and by extension all 8NN) numbers became "portable." That means that customers can take their 800 telephone number from one long distance company to another, and still keep the same 800. See also 800 Portability.

800 Services are known internationally as "Freefone Services." In other countries the dialing scheme may vary, with examples being 0-800 and 0-500. Such services also go under the name "Greenfone." In June 1996, the ITU-T approved the E.169 standard Universal International Freefone Number (UIFN) numbers, also known as "Global 800." UIFN will work across national boundaries, based on a standard numbering scheme of 800, 888 or 877 plus an 8-digit telephone number. See also UIFN and Vanity Numbers.

802

See 802 Standards.

802 Standards

The 802 Standards are a set of standards for LAN (Local Area Network) and MAN (Metropolitan Area Network) data communications developed through the IEEE's Project 802. The two most important standards are 802.11b and 802.11a. The standards also include an overview of recommended networking architectures, approved in 1990. The 802 standards follow a unique numbering convention. A number followed by a capital letter denotes a standalone standard; a number followed by a lower case letter denotes either a supplement to a standard, or a part of a multiple-number standard (e.g., 802.1 & 802.3). The 802 standards segment the data link layer into two sublayers :

A Media Access Control (MAC) layer that includes specific methods for gaining access to the LAN. These methods ” such as Ethernet's random access method and Token Ring's token passing procedure ” are in the 802.3, 802.5 and 802.6 standards.

A Logical Link Control (LLC) Layer, described in the 802.2 standard, that provides for connection establishment, data transfer, and connection termination services. LLC specifies three types of communications links:

• An Unacknowledged Connectionless Link, where the sending and receiving devices do not set up a connection before transmitting. Instead, messages are on a "best effort" basis, with no provision for error detection, error recovery, or message sequencing. This type of link is best suited for applications where the higher layer protocols can provide the error correction and functions, or where the loss of broadcast messages is not critical.

• A Connection-Mode Link, where a connection between message source and destination is established prior to transmission. This type of link works best in applications, such as file transfer, where large amounts of data are being transmitted at one time.

• An Acknowledged Connectionless Link that, as its name indicates, provides for acknowledgement of messages without burdening the receiving devices with maintaining a connection. For this reason, it is most often used for applications where a central processor communicates with a large number of devices with limited processing capabilities.

802.1

IEEE standard for overall architecture of LANs and internetworking. See all the following definitions.

802.11a

802.11a is an updated, bigger, better, faster version of 802.11b (also called WiFi), which is now commonly installed in offices, airports, coffee shops , etc. Many laptops now come with 802.11b built-in. The newer 802.11a, also an IEEE standard for wireless LANs, supports speeds up to 54 Mbps. 802.11a runs in a 300-MHz allocation in the 5 GHz range, which was allocated by the FCC in support of UNII (the Unlicensed National Information Infrastructure). Specifically , 200 MHz is allocated at 5.15-5.35 MHz for in-building applications, and 100 MHz at 5.725-5.825 MHz for outdoor use. This allocated spectrum is divided into three working domains. At 5.15-5.25 MHz, maximum power output is restricted to 50mW (milliWatts), 5.25-5.35 to 250mW, and 5.725- 5.825 to 1 Watt. 802.11a has been dubbed Wi-Fi5 (Wireless Fidelity 5 MHz) by the Wireless Ethernet Compatibility Alliance (WECA).

802.11a uses Coded Orthogonal Frequency Division Multiplexing (COFDM) as the signal modulation technique. COFDM sends a stream of data symbols in a massively parallel fashion, with multiple subcarriers (i.e., small slices of RF, or Radio Spectrum, within the designated carrier frequency band . Each carrier channel is 20 MHz wide, and is subdivided into 52 subcarrier channels, each of which is approximately 300 KHz wide; 48 of the sub- carrier channels are used for data transmission, and the remaining four for error control. Through the application of a coding technique, each symbol comprises multiple data bits. The specified coding techniques and data rates specified, all of which must be supported by 802.11-compliant products, include BPSK (Binary Phase Shift Keying) at 125 Kbps per channel for a total of 6 Mbps across all 48 data channels, QPSK (Quadrature Phase Shift Keying) at 250 Kbps per channel for a total of 12 Mbps, and 16QAM (16-level Quadrature Amplitude Modulation) at 500 Kbps per channel for a total of 24 Mbps. The standard also allows more complex modulation schemes, that offer increased data rates. Currently, the most complex and fastest is 64QAM (64-level QAM), at 1.125 Mbps per channel for a total of 54 Mbps.

The symbol rate is slowed down enough that each symbol transmission is longer than the delay spread. The delay spread is the variation in timing between receipt of the signals associated with a given symbol, with the delay spread caused by multipath fading. Multipath fading is the phenomenon whereby the RF signals carrying a given data symbol arrive at the receiver at slightly different times. This is because the signal spreads out from the transmitter, with certain portions of the signal reaching the receiver more or less directly, while other portions of the signal bounce around off of walls, furniture, your co-worker's pointy head, and such. Now, each of the symbols contains multiple bits, which are imposed on it through the coding processes identified above. As the multiple symbols reach the receiver, they are sorted out and decoded, with the decoding process providing some additional time for the receiver to adjust for the delay spread and to get ready to receive the next symbol. Both 802.11a and 802.11b are designed to be compatible with Ethernet LANs, using the MAC (Media Access Control) technique of CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance).

If this sounds great, that's because it is great. If this sounds too good to be true, that's because it gets a little more complicated. While the 5 GHz spectrum is pretty clear in the US, it's not so readily available elsewhere. Military and government installations use portions of this band overseas. In Japan, only the 5.15-5.25 MHz spectrum is available. In Europe, the 5.725-5.825 MHz spectrum is already allocated for other uses. In Europe, ETSI (European Telecommunications Standards Institute) requires that two additional protocols be used in conjunction with 802.11a in order to protect incumbent applications and systems running over previously allocated shared spectrum. DFS (Dynamic Frequency Selection) allows the 802.11a system to dynamically shift frequency channels and TPC (Transmission Power Control) reduces the power level. In combination, these protocols serve to eliminate interference issues with incumbent signals. See also 802.11b, 802.11g, BPSK, CSMA/CA, MAC, OFDM, QAM, QPSK, WECA and Wi-Fi.

802.11b

802.11b is now the most common wireless local area network. 802.11b is now installed in offices, airports, coffee shops, hotels, boardrooms and homes . Many lap- tops now come with 802.11b wireless transmit and receive electronics built-in. 802.11b is also called Wi-Fi or WiFI (Wireless Fidelity). 802.11b is a low power wireless system so the closer you are to a transmitter, the faster it will be. This is roughly what you'll get: Wireless operating range (indoors): 100 feet at 11 Mbps, 165 feet at 5.5 Mbps, 230 feet at 2 Mbps, 300 feet at 1 Mbps. Wireless operating range (outdoors): 500 feet at 11 Mbps, 885 feet at 5.5 Mbps, 1,300 feet at 2 Mbps, 1,500 feet at 1 Mbps. 802.11b operates at the same frequency as some cordless phones, garage door openers, walkietalkies, etc. So there's a real chance for interference in big cities, like New York. An 802.11b basestation is often attached to a local area network, which is then attached to the Internet and/or the corporate network. This means that you use 802.11b to surf the Internet or get to corporate databases, etc.

802.11b defines both the Physical (PHY) and Medium Access Control (MAC) protocols. Specifically, the PHY spec includes three transmission options ” one Ir (Infrared), and two RF (Radio Frequency). 802.11b uses DSSS (Direct Sequence Spread Spectrum) modulation for digital communication. DSSS involves the transmission of a stream of one's and zero's, which is modulated with the Barker code chipping sequence. Barker code is an 11- bit sequence (e.g., 10110111000) that has advantages in wireless transmission. Each bit is encoded into an 11-bit Barker code, with each resulting data object forming a "chip." The chip is put on a carrier frequency in the 2.4 GHz range (2.4-2.483 GHz), and the waveform is modulated using one of several techniques. 802.11 systems running at 1 Mbps make use of BPSK (Binary Phase Shift Keying). Systems running at 2 Mbps make use of QPSK (Quaternary Phase Shift Keying). Systems running at 11 Mbps make use of CCK (Complementary Code Keying), which involves 64 unique code sequences, which technique supports six bits per code word. The CCK code word is then modulated onto the RF carrier using QPSK, which allows another two bits to be encoded for each 6-bit symbol. Therefore, each 6-bit symbol contains eight bits. Power output is limited by the FCC to 1 watt EIRP (Equivalent Isotropically Radiated Power). At this low power level, the physical distance between the transmitting devices becomes an issue, with error performance suffering as the distance increases . Therefore, the devices adapt to longer distances by using a less complex encoding technique, and a resulting lower signaling speed, which translates into a lower data rate. For example, a system running at 11 Mbps using CCK and QPSK, might throttle back to 5.5 Mbps by halving the signaling rate as the distances increase and error performance drops . As the situation gets worse , it might throttle back to 2 Mbps using only QPSK, and 1 Mbps using BPSK. Also to be considered in this equation is the fact that the 2.4 GHz range is in the unlicensed ISM (Industrial, Scientific and Medical) band, which is shared by garage door openers, microwave ovens, bar code scanners , cordless phones, Bluetooth LANs, and a wide variety of other devices. As a result, this slice of spectrum can be heavily congested at times, and performance can drop considerably. 802.11 divides the available spectrum into 14 channels. In the US, the FCC allows the use of 11 channels. Four channels are available in France, 13 in the rest of Europe, and only one in Japan. There also is overlap between adjacent channels (e.g., channels one and two), which fact further affects performance; therefore, any given system must maintain maximum channel separation from other systems in proximity.

Both 802.11a and 802.11b are designed to be compatible with Ethernet LANs. 802.11b uses a variation of the MAC (Media Access Control) technique of CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance), which is used in some wired Ethernets, as well. A device seeking to transmit over the shared medium (in this case, a shared RF channel) listens to the network. If it senses no activity over the carrier frequency for a minimum period of time known as the DIFS (DCF (Distributed Coordinated Function) InterFrame Spacing), it requests access by first transmitting a RTS (Request To Send) packet. The RTS packet includes both the source (i.e., transmitter) and destination (i.e., intended receiver) addresses, the duration of the intended session (i.e., transmission), and the ACK (ACKnowledgement) associated with it. If the network is available, the destination device responds with CTS (Clear To Send), repeating both the duration and the ACK. All other devices back off the network until the session is concluded. If the network, on the other hand, is busy, the device waits a period of time equal to the DIFS, plus a random number of slot times, as calculated with several back-off timers. The "listening" process takes several forms. CAM (Constant Access Method), the default method, involves constant monitoring of the network. Since CAM creates a power consumption issue for battery- powered devices, PAM (Polled Access Mode) can be substituted. PAM calls for all client devices to go into sleep mode, all awaking at regular intervals, at the exact same time, to listen for network activity. On January 3, 2000 the 802.11 technology got another boost when Microsoft and Starbucks announced that they were to join forces to offer wireless access, using 802.11b among other standards, in most of Starbucks' coffee outlets over the next two years. The deal, some analysts say, is a further sign that 802.11b could become a serious competitor to better known wireless technologies such as Bluetooth, HomeRF, or even next-generation cellular networks. Apple was the first to launch an 802.11b product line (called AirPort). All Apple computers now include a built-in antenna which, in conjunction with a networking card, can exchange data with a small base station plugged into a broadband Internet connection up to 45 metros (150 feet) away. Although some PC laptops now come pre-equipped with wireless hardware, most users buy a PCMCIA card, or PC card, that serves as a wireless modem and antenna. See also 802.11a, 802.11g, Bluetooth, BPSK, Chip, CSMA/CA, DSSS, EIRP, Ethernet, HomeRF, MAC, QPSK, Spread Spectrum, WECA and Wi-Fi.

802.11g

In November, 2001, Task Group G of the IEEE's 802.11 Committee voted to finish the specs on a new wireless networking standard (802.11g) that would allow wireless data rates up to 54 megabits per second in the 2.4 GHz spectrum. Current 802.11b Wi-Fi systems have a maximum data rate of 11 megabits per second. The proposed will be compatible with 802.11b. Mandatory modulation schemes of the proposed standard are Complementary Code Keying (CCK), used in 802.11b, and Orthogonal Frequency Division Multiplexing (OFDM), used in 802.11a. Two optional modulations are allowed if systems manufacturers chose to add them: CCK-OFDM and CCK-PBCC. The new standard 802.11g is important because 802.11a and 802.11b are incompatible, but 802.11g devices will work with both 802.11a and 802.11b devices. On May 15, 2003, the Institute of Electrical and Electronics Engineers Inc. (IEEE), the group responsible for setting standards in the networking industry, approved a new and final draft standard for 802.11g wireless LANs.

802.11i

The IEEE's 802.11i working group is developing (or was when I wrote this) a far-reaching standards-based solution for both encryption and authentication on wireless 802 LANs.

802.12

Standard for 100VG-AnyLAN. Addresses 100 Mbps demand-priority access method physical-layer and repeater specifications. Approved in 1995.

802.15.1

The 802.15.1 is an IEEE standard for wireless personal area networks. Basically it is an enhanced Bluetooth v1.1 specification and it is fully compatible with the Bluetooth v1.1 specification. Bluetooth technology defines specifications for small-form-factor, low-cost wireless radio communications among notebook computers, personal digital assistants, cellular phones and other portable, handheld devices, and connectivity to the Internet. "The new standard gives the Bluetooth specification greater validity and support in the market and is an additional resource for those who implement Bluetooth devices," says Ian Gifford, IEEE 802.15 Working Group Vice Chair. "This collaboration is a good example of how a standards development organization and a special industry group (SIG) can work together to improve an industry specification and also create a standard. The IEEE standard also added a major clause on Service Access Points, which includes an LLC/MAC interface for the ISO/IEC 8802-2 LLC, a normative annex that provides a protocol implementation conformance statement (PICS) pro forma, and an informative, high-level behavioral ITU-T Z.100 specification and description language (SDL) model for an integrated Bluetooth MAC Sublayer. This SDL model offers an extensive overview (more than 500 pages long) of a significant portion of the Bluetooth protocols e.g., Baseband, LMP, L2CAP, and the Link Manager (using the host controller interface (HCI)). The IEEE-SA plans to further develop the 802.15.1 SDL model source to support the standard. The SDL code, which will be available on CD-ROM, will include a computer model for use with any SDL tool that supports the SDL-88, SDL-92 or SDL-2000 update of ITU-T Recommendation Z.100. The IEEE 802.15.1 Working Task Group used the SDL (Specification and Description Language) to translate the natural language of the Bluetooth Specification into a formal specification that defines how the Bluetooth protocols react to events in the environment that are communicated to a system by signals.

802.15.3

A standard developed to meet the requirements of portable consumer imaging and multimedia applications ” what the IEEE refers to as the standard for High Rate Wireless Personal Area Networks (WPANs). (The IEEE defines High Rate as 20 Mbps or better.) It is based on a centralized and connection-oriented ad-hoc networking topology. The standard also supports peer-to-peer connectivity and isochronous and asynchronous data. 802.15.3 is optimized for low-cost, small-form factor, and low-power consumer devices, enabling multimedia applications that are not optimized by existing wireless standards. The current technology will operate in the unlicensed 2.4 GHz band and supports five selectable data rates; 11, 22, 33, 44, and 55 Mbps, as well as three to four non-overlapping channels. The standard is secure, implementing privacy, data integrity, mutual-entity authentication and data-origin authentication for consumer applications. Task Group 3a (TG3a) has been charged to define an enhancement amendment for even higher speeds.

802.15.4

The IEEE 802.15 TG4 (Task Group 4) is chartered to investigate a low data rate solution with multi-month to multi-year battery life and very low complexity. Intended to operate in an unlicensed, international frequency band, the standard will support sensors, interactive toys, smart badges, remote controls and home automation. This is an important standard which will extend wireless communications to low-power, low-cost, low- speed devices ” like sensors and switches for industrial and residential use to smart tags and badges, interactive toys, inventory tracking and much more. 802.15.4 provides for low-data-rate connectivity among relatively simple devices that consume minimal power and typically connect at distances of 10 meters (30 feet) or less and operating at data rates of 10 to 250 kbps. It allows devices to form short-range ad hoc networks within which they can interact directly. "This is an enabling standard," says Pat Kinney, Chair of IEEE 802.15 Task Group 4. "It builds a framework so existing low-end wired devices can participate in wireless networks and also creates a path for many new applications. The potential uses have several things in common. They all involve relatively simple, low-speed wireless links that need so little power that a set of AA batteries might last three to five years or even longer. "We believe a host of new applications will be based on the standard. These might include motion sensors that control lights or alarms, wall switches that can be moved at will, meter reader devices that work from outside a house, game controllers for interactive toys, tire pressure monitors in cars, passive infrared sensors for building automation systems, and asset and inventory tracking devices for use in retail stock rooms and warehouses."

802.16

IEEE standard for Wireless MAN air interface. Covers 10 GHz to 66 GHz wireless networks. The first broadband wireless access standard to be developed and released by an accredited standards body. 802.16 features a protocol-independent core, supports high-bandwidth on-demand environments, hundreds of users per channel and can handle either continuous or bursty traffic. Now called WiMAX. See WiMAX for a fuller explanation.

802.16a

A developing amendment to the 802.16 IEEE standard for broadband wireless access covering 2 GHz to 11 GHz wireless networks. See 802.16.

802.17

A technological specification being developed by the IEEE for Resilient Packet Ring (RPR), 802.17 is intended to optimize Ethernet-based metropolitan ring networks for packet transport with resiliency matching or exceeding that of SONET rings. RPR will carry voice and other TDM (Time Division Multiplexed) traffic with the QoS (Quality of Service) and resiliency of SONET and ATM combined, while supporting LAN traffic with the efficiency of Ethernet.

802.1B

Standard for LAN/WAN management, approved in 1992; along with 802.1k, became the basis of ISO/IEC 15802-2.

802.1D

IEEE standard for interconnecting LANs through MAC bridges (specifically between 802.3, 802.4, and 802.5 networks). The standard was approved in 1990, and was incorporated into ISO/IEC 10038. Works at the MAC level. See Spanning Tree.

802.1E

IEEE standard for LAN and MAN load protocols. Approved in 1990, formed the basis for ISO/IEC 15802-4.

802.1F

Standard for defining network management information specified in 802 umbrella standards. Approved in 1993.

802.1G

A developing standard for remote bridging at the MAC layer.

802.1H

IEEE practices recommended for bridging Ethernet LANs at the MAC layer. Approved in 1995.

802.1I

IEEE standard for using FDDI (Fiber Distributed Data Interface) as a MAC-layer bridge. Approved in 1992, the standard was incorporated into ISO/IEC 10038.

802.1J

IEEE standard for LAN connectivity using MAC-layer bridges. A supplement to 802.1D, it was approved in 1996.

802.1K

IEEE standard for the discovery and dynamic control of network management information. Approved in 1993. In conjunction with 802.1B, was the basis for ISO/IEC 15802-2.

802.1M

A conformance statement for 802.1E, it addresses definitions and protocols for system load management. Approved in 1993, it was incorporated into ISO/IEC 15802-4.

802.1P

802.1P is an IEEE standard for providing quality of service (QoS) in 802-based networks. 802.1p uses three bits (defined in 802.1q) to allow switches to reorder packets based on priority level. It also defines the Generic Attributes Registration Protocol (GARP) and the GARP VLAN Registration Protocol (GVRP). GARP lets client stations request membership in a multicast domain, and GVRP lets them register into a VLAN. 802.1p is an IEEE extension of 802.1D. It is the specification for the use of MAC-layer bridges in filtering and expediting multicast traffic. Prioritization of traffic is accomplished through the addition of a 3-bit, priority value in the frame header. Eight topology-independent priority values (0-7) are specified, with all eight values mapping directly into 802.4 and 802.6. Switches that support 802.1P and 802.1Q provide a framework for bandwidth prioritization. Essentially what all these words mean is that you can assign a priority to the type of traffic with IEEE 802.1p class-of-service (CoS) values and these allow network devices along the way to recognize and deliver high-priority traffic in a predictable manner. When congestion occurs, QoS drops low-priority traffic to allow delivery of high-priority traffic. See also 802.1Q.

802.1Q

An IEEE standard for providing VLAN identification and quality of service (QoS) levels. Four bytes are added to an Ethernet frame, increasing the maximum frame size from 1518 to 1522 bytes. Three bits are used to allow eight priority levels (QoS) and 12 bits are used to identify up to 4096 VLANs. 802.1q is the IEEE specification for implementation of VLANs (Virtual Local Area Networks) in Layer 2 LAN switches, with emphasis on Ethernet. Similar to 802.1P, prioritization of traffic is accomplished through an additional four bytes of data in the frame header. Most data fields in this addition to the header are specific to VLAN operation. Also included is a field which provides the same 3-bit priority flag specified in 802.1P's priority-mapping scheme. In addition to conventional data traffic, 802.1Q supports voice and video transmission through Ethernet switches. In short, the 802.1Q specification provides a 32-bit header for VLAN frame tagging. Each 802.1Q tag sits in an Ethernet frame between the source address field and the media access control (MAC) client type/length field. An important feature of 802.1Q is the ability to share multiple subnets across a high-speed link. This capability not only reduced the number of lower speed links needed for physical separation, but it also allowed for asymmetrical traffic management so that different speed links could be managed more easily. With IEEE 802.1p and 802.1Q, we saw the introduction of some important concepts that have been carried forward for further QoS (Quality of Service) development. These 802.1 features also can be mapped into higher layer protocols like IP and ATM.

802.1X

802.1X is an attempt to introduce serious security checking into today's very popular wireless 802.11 LANS (also called WiFi LANs) by making sure that users of the LANs are clean and honest folks and, most importantly, allowed to use the LAN. Current authentication in the 802.11 standard is focused more on wireless LAN connectivity (i.e. getting the LAN working) than on verifying user or station identity. For wireless LANs to grow large, i.e. to scale to hundreds or thousands of users, the current method of authentication must be replaced by an authentication framework that supports centralized user authentication. And that's what 802.1X is all about. Task Group I of the IEEE 802.11 committee is working on 802.1X, an IEEE standard that provides an authentication framework for 802-based LANs. 802.1X will let wireless LANs scale by allowing centralized authentication of wireless users or stations. The standard is flexible enough to allow multiple authentication algorithms, and because it is an open standard, multiple vendors can innovate and offer enhancements. 802.1X takes advantage of an existing authentication protocol known as the Extensible Authentication Protocol (EAP ”RFC 2284). 802.1X takes EAP, which is written around PPP, and ties it to the physical medium, be it Ethernet, Token Ring or wireless LAN. EAP messages are encapsulated in 802.1X messages and referred to as EAPOL, or EAP over LAN. 802.1X authentication for wireless LANs has three main components : The supplicant (usually the client software); the authenticator (usually the access point); and the authentication server (usually a Remote Authentication Dial-In User Service server, although RADIUS is not specifically required by 802.1X). The client tries to connect to the access point. The access point detects the client and enables the client's port. It forces the port into an unauthorized state, so only 802.1X traffic is forwarded. Traffic such as Dynamic Host Configuration Protocol, HTTP, FTP, Simple Mail Transfer Protocol and Post Office Protocol 3 is blocked. The client then sends an EAP-start message. The access point will then reply with an EAP-request identity message to obtain the client's identity. The client's EAP-response packet containing the client's identity is forwarded to the authentication server. The authentication server is configured to authenticate clients with a specific authentication algorithm. The result is an accept or reject packet from the authentication server to the access point. Upon receiving the accept packet, the access point will transition the client's port to an authorized state, and traffic will be forwarded. 802.1X for wireless LANs makes no mention of key distribution or management. This is left for vendor implementation. At logoff, the client will send an EAP- logoff message. This will force the access point to transition the client port to an unauthorized state.

In short, 802.1X is a June, 2001 IEEE specification for port-based network access control. 802.1X makes use of the physical access characteristics of IEEE 802 LANs to provide a mechanism for authenticating and authorizing attached devices with point-to-point connection characteristics, and of preventing access to that port should the authentication and authorization processes fail. The LAN ports can be either physical (i.e., hard-wired) or logical (i.e., wireless) in nature. 802.1X is particularly aimed at the ports of MAC bridges as specified in 802.1D, the ports used to attach servers or routers to the LAN, and the associations between wireless stations and access points in 802.11 WLANs (Wireless LANs). Applications include corporations that provide LAN access to the public in certain areas, and service providers that offer high-speed Internet access in hotels and airports. 802.11 makes use of the Extensible Authentication Protocol (EAP), as specified in RFC2284. The EAP messages are encapsulated in 802.1X messages, thereby taking the form of EAPOL (EAP Over LAN). The authentication procedure commonly involves a supplicant (generally client software) communicating with a wireless access point that consults with an authentication server, which usually is in the form of a RADIUS (Remote Access Dial In User Service) server. See also 802.11, 802.1D, EAP, EAPOL and RADIUS.

802.2

The IEEE standard for Logical Link Control, primarily using MAC-layer bridges, in LAN and MAN domains. Originally approved in 1989, and updated in 1994. A format used for frames of data sent on Ethernet, token ring and several other types of local area networks. Now the format favored by Novell for NetWare 4.x LANs over the 802.3.

802.2 SNAP

(Cub-Network Access Protocol). A variation on the 802.2/802.3 scheme which expands the 802.2 LLAMA header to provide sufficient space in the header to identify almost any network protocol.

802.3

IEEE standard for carrier sense multiple access with collision detection (CSMA/CD). A physical layer standard specifying a LAN with a CSMA/CD access method on a bus topology. Ethernet and Starlan both follow the 802.3 standard. Typically they transmit at 10 megabits per second (Mbps). The theoretical limit of Ethernet, measured in 64 byte packets, is 14,800 packets per second (PPS). By comparison, Token Ring is 30,000 and FDDI is 170,000. 802.3 forms the basis for ISO/IEC 8802-3.

802.3 1Base5

IEEE standard for baseband Ethernet at 1 Mbps over twisted pair wire to a maximum distance of 500 meters. Also called Starlan.

802.3 10Base-5

IEEE standard for baseband Ethernet at 10 Mbps over coaxial cable to a maximum distance of 500 meters.

802.3 10Base-T

Also called 802.3i. 10Base-T is an IEEE standard for operating Ethernet local area networks (LANs) on twisted-pair cabling using the home run method of wiring (exactly the same as a phone system uses) and a wiring hub that contains electronics performing similar functions to a central telephone switch. The full name for the standard is IEEE 802.3 10Base-T. The 10Base-T standard, issued in the fall of 1990, defined the requirements for sending information at 10 million bits per second on ordinary unshielded twisted-pair cabling. The 10Base-T standard defines various aspects of running Ethernet on twisted-pair cabling such as:

• Connector types (typically eight-pin RJ-45),

• Pin connections (1 and 2 for transmit, 3 and 6 for receive),

• Voltage levels (2.2 volts to 2.8 volts peak), and

• Noise immunity requirements to filter outside interference from telephone lines or other electronic equipment.

Ethernet is the most popular LAN in the world. Ethernet running on loop coaxial cable ” typically called thin Ethernet or thinnet ” is the most popular way of running Ethernet local area networks. Loop networks suffer from the major problem that one cut in the cable can destroy the complete network. 10Base-T is a much more reliable ” though more expensive ” way of connecting LANs, since it requires electronics at the center of the home run. As I write this, the most common form of 10Base-T electronics is a small box joining about 12 workstations together. To get more on the LAN, you simply daisy chain the boxes together. The boxes are unbelievably reliable. They're easy to install and they often come with LAN management software, which gives you statistics on who's using the network, for how long, what the performance is, and what potential problems might crop up, etc. The cable 10Base-T networks use to connect between their central electronics and their attached workstations is typically standard twisted pair phone wiring, which is a lot easier to install than coaxial cable. 10Base-T networks are now becoming most popular and are being installed at faster rate than old-style loop coaxial wired LANs. For a fuller explanation see Ethernet.

802.3 10Broad36

IEEE standard for broadband Ethernet at 10 Mbps over broadband cable to a maximum distance of 3600 meters.

802.3ae

10 Gigabit Ethernet standard - offering data speeds up to 10 billion bits per second. Built on the Ethernet technology used in most of today's LANs, 10-Gigabit Ethernet is described as a "disruptive" technology that offers a more efficient and less expensive approach to moving data on backbone connections between networks while also providing a consistent technology end-to-end. Using optical fiber, 10-Gigabit Ethernet is being positioned to replace existing networks that use ATM switches and SONET multiplexers on an OC-48 SONET ring with a simpler network of 10-Gigabit Ethernet switches and at the same time improve the data rate from 2.5 Gbps to 10 Gbps. 10-Gigabit Ethernet is expected to be used to interconnect LANs, wide area networks (WANs), and metropolitan area networks (MANs). 10-Gigabit Ethernet uses the IEEE 802.3 Ethernet media access control (MAC) protocol and its frame format and size. On multimode fiber, 10-Gigabit Ethernet will support distances up to 300 meters. On single mode fiber, it will support distances up to 40 kilometers. Smaller Gigabit Ethernet networks can feed into a 10-Gigabit Ethernet network. There are seven faces of 10 Gigabit Ethernet:

Interface	Type	PM D (nm)	PHY	Fiber type/diameter (microns)	Range (meters)
10Gbase-SR	Serial	850	LAN	Multimode/50	65
				Multimode/62.5	26
10Gbase-LR	Serial	1,310	LAN	Single mode/9	10,000
10Gbase-ER	Serial	1,550	LAN	Single mode/9	40,000
10Gbase-LX4	WWDM	1,310	LAN	Single mode/9	10,000
				Multimode/62.5	300
10Gbase-SW	Serial	850	WAN	Multimode/50	65
				Multimode/62.5	26
10Gbase-LW	Serial	1,310	WAN	Single mode/9	10,000
10Gbase-EW	Serial	1,550	WAN	Single mode/9	40,000

802.3af

This proposed IEEE standard is designed to power network devices over Ethernet wiring. The standard defines two types of power sourcing equipment ” end-span and mid-span. The major objective of this new standard is to making deploying IP telephones and wireless access points easier and reduce the cost of powering the devices. Traditionally, IP phones and wireless access points have required two connections ” one to the LAN and another to AC electricity. For example, you may wish to place your wireless access point up in the ceiling. But getting AC power up there is expensive. It's clearly easier to run a single RJ-45 cord up to the ceiling. End-span refers to an Ethernet switch with embedded Power over Ethernet technology. These new switches deliver data and power over the same wiring pairs ” transmisison pairs 1/2 and 3/6. Mid-span devices resemble patch panels and typically have been six and 24 channels. They are placed betwen legacy switches and powered devices. Each of the mid-span ports has an RJ-45 data input and a data/power RJ-45 output connector. Mid-span devices tap the unused wire pairs 4/5 and 7/8 to carry power, while data runs on the other wire pairs.

802.3ah

An IEEE standard for delivering Ethernet over copper in the first mile, dubbed "Ethernet in the First Mile". The standard is designed to use existing infrastructure (i.e. copper wire) to provide higher speeds over ” speeds as fast as 100 megabits per second. The idea is that if phone companies can use wiring they already have to provide Ethernet at 10Mbps to customers instead of DSL or T1 lines, and do it at significantly lower costs, they will. This standard will support Category 3 cable (standard, voice-grade phone wires) to 750 meters. In addition, the standard will support 100Mbps and 1Gbps Ethernet over optical fiber. To keep costs down, the EFMA development alliance is also proposing a standard for Ethernet over a single strand of fiber, in addition to the dual-strand fibers currently in use. Single-strand fiber would work by using different wavelengths of light on the same strand for the two directions, instead of using the same wavelength over two separate strands of fiber, as in the current dual- strand practice. In either case, the EFMA's proposed standard calls for fiber runs as long as 10 kilometers. The current thinking of the 802.3ah committee is that these fibers would aggregate many 10Mb copper drops ” with only half as much fiber. There's also support for passive optical networks in the 802.3ah proposal. This standard would allow several users of Gigabit Ethernet to share a single fiber for as many as 20 kilometers, using passive splitters to aggregate and separate traffic.

802.3b

IEEE standard for 10Broad36. Approved in 1985, it is the standard for broadband Ethernet at 10 Mbps over coaxial cable to a maximum distance of 3600 meters. It was incorporated into ISO/IEC 8802-3.

802.3c

Standard for 10 Mbps baseband repeaters. The standard was approved in 1985, and is incorporated into ISO/IEC 8802-3.

802.3d

IEEE standard for media attachment devices and baseband media over fiber optic repeater links. Approved in 1987, it has been incorporated into ISO/IEC 8802-3.

802.3e

IEEE standard for 1Base-5, baseband Ethernet at 1 Mbps over twisted pair wire to a maximum distance of 500 meters. Also called Starlan. The standard addresses physical media, physical signaling and media attachment. Approved in 1987, it is incorporated into ISO/IEC 8802-3.

802.3h

Standard for layer management in CSMA/CD networks. Approved in 1990, it has been incorporated into ISO/IEC 8802-3.

802.3i

The IEEE standard addressing multisegment 10 Mbps networks, and twisted-pair media for 10Base-T networks. 10Base-T is an IEEE standard for operating Ethernet local area networks (LANs) on twisted-pair cabling using the home run method of wiring (exactly the same as a phone system uses) and a wiring hub that contains electronics performing similar functions to a central telephone switch. The full name for the standard is IEEE 802.3 10Base-T. The 10Base-T standard, issued in the fall of 1990, defined the requirements for sending information at 10 million bits per second on ordinary unshielded twisted-pair cabling; the standard has been incorporated into ISO/IEC 8802-3. The 10Base-T standard defines various aspects of running Ethernet on twisted-pair cabling such as:

• Connector types (typically eight-pin RJ-45),

• Pin connections (1 and 2 for transmit, 3 and 6 for receive),

• Voltage levels (2.2 volts to 2.8 volts peak), and

• Noise immunity requirements to filter outside interference from telephone lines or other electronic equipment.

Ethernet is the most popular LAN in the world. Ethernet running on loop coaxial cable ” typically called thin Ethernet or thinnet ” is the most popular way of running Ethernet local area networks. Loop networks suffer from the major problem that one cut in the cable can destroy the complete network. 10Base-T is a much more reliable ” though more expensive ” way of connecting LANs, since it requires electronics at the center of the home run. As I write this, the most common form of 10Base-T electronics is a small box joining about 12 workstations together. To get more on the LAN, you simply daisy chain the boxes together. The boxes are unbelievably reliably. They're easy to install and they often come with LAN management software, which gives you statistics on who's using the network, for how long, what the performance is, and what potential problems might crop up, etc. The cable 10Base-T networks use to connect between their central electronics and their attached workstations is typically standard twisted pair phone wiring, which is a lot easier to install than coaxial cable. 10Base-T networks are now becoming most popular and are being installed at faster rate than old-style loop coaxial wired LANs. For a fuller explanation see Ethernet.

802.3j

IEEE standard for 10Base-F, which provides for fiber optics links connecting 10 Mbps active and passive starbased baseband networks. The standard was approved in 1993 and is incorporated into ISO/IEC 8802-3.

802.3k

IEEE standard for layer management for repeaters in 10 Mbps baseband networks. It was approved in 1992 and is incorporated into ISO/IEC 8802-3.

802.3l

A conformance statement for the media attachment unit protocol for 10Base-T networks. The statement was approved in 1992 and is incorporated into ISO/IEC 8802- 3.

802.3p

IEEE standard for media attachment unit layer management for 10 Mbps baseband networks. The standard was approved in 1992 and is incorporated into ISO/IEC 8802-3.

802.3q

Provides guidelines for the development of managed objects. Approved in 1993, it was incorporated into ISO/IEC 8802-3.

802.3r

IEEE standard for CSMA/CD and physical media specifications for 10Base-5, which is baseband Ethernet at 10 Mbps over fat coaxial cable to a maximum distance of 500 meters. This version of the original Ethernet standard was updated in 1996.

802.3t

Standard for 120-ohm cables in 10Base-T simplex links. Approved in 1995, it was incorporated into ISO/IEC 8802-3.

802.3u

A supplement to 802.3 that governs Carrier Sense Multiple Access/Collision Detection (CSMA/CD) for 100 Mbps networks, i.e., 100Base-T, commonly known as Fast Ethernet. Approved in 1995, this supplement covers the specification's MAC parameters, the physical layer, and repeaters for 100Base-T4, TX, and FX.

802.3v

IEEE standard for 150-ohm cables in 10Base-T link segments. Approved in 1995, it was incorporated into ISO/IEC 8802-3.

802.3z

Gigabit Ethernet over fiber standard, ratified on June 29, 1998. See Gigabit Ethernet.

802.4

IEEE physical layer standard specifying a LAN with a token-passing access method on a bus topology. It is typically used with Manufacturing Automation Protocol (MAP) LANs. MAP was developed by General Motors. Typical transmission speed is 10 megabits per second.

802.5

IEEE physical layer standard specifying a LAN with a token-passing access method on a ring topology using unshielded twisted pair. Used by IBM's Token Ring hardware. Typical transmission speed is 4 or 16 megabits per second. IEEE physical layer standard specifying a LAN with a token-passing access method on a ring topology using unshielded twisted pair. The standard became the basis for ISO/IEC 8802-5. The current version of 802.5 was approved in 1995.

802.6

IEEE standard for MANs (Metropolitan Area Networks). Formerly known as QPSX (Queued Packet and Synchronous Exchange), now known as DQDB (Distributed Queue Dual Bus). It was approved in 1990.

802.7

IEEE technical advisory group on broadband LANs.

802.8

IEEE technical advisory group for fiber-optic LANs.

802.9

IEEE technical advisory on ISLAN, which stands for Integrated Services LAN. ISLAN is Isoethernet with switched or packetized voice on an Ethernet LAN, which is 10 megabits per second of Ethernet (used for data) plus six megabits per second of ISDN B channels, which gives you 96 B ISDN channels plus a D channel. You can use the B channels for voice.

802.X

The Institute of Electrical and Electronics Engineers (IEEE) committee that developed a set of standards describing the cabling, electrical topology, physical topology, and access scheme of network products; in other words, the 802.X standards define the physical and data-link layers of LAN (local area network) architectures. Or, in simple language, the set of IEEE standards for the definition of LAN protocols. IEEE 802.3 is the work of an 802 subcommittee that describes the cabling and signaling for a system nearly identical to classic Ethernet. IEEE 802.5 comes from another subcommittee and similarly describes IBM's Token-Ring architecture.

811

The telephone number some, but by no means all, telephone companies use for their business office. See also N11.

822

Short form of RFC 822. Refers to the format of Internet style e-mail as defined in RFC 822.

82596

The 82596 is an intelligent, 16-/32-bit local area network coprocessor from Intel. The 82596 implements the CSMA/CD access method and can be configured to support all existing 802.3 standards. Coupled with the 82503 Dual Serial Transceiver, the 82596 provides the optimal Ethernet connection to Intel1386 and Intel486 client PCs and servers. The board space required for an 82596/82503 motherboard implementation is less than six square inches. Provides full Ethernet bandwidth performance while allowing the CPU to work independently. An on-board four-channel DMA controller along with an intelligent micro machine automatically manages memory structures and provides command chaining and autonomous block transfers while two large independent FIFOs accommodate long bus latencies and provide programmable thresholds.

855 Service

A North American toll-free area code. This fifth such area code was to be introduced in November 2000, but was delayed until at least February 2001 by FCC order. See 800 Service for a full explanation.

866 Service

A North American toll-free area code. This fourth such area code was introduced in July 2000. See 800 Service for a full explanation.

877 Service

A North American toll-free area code. The original such area code was 800 numbers. Introduced in 1967, the 800 area code was sufficient for about 30 years. The NANP (North American Numbering Plan) was expanded in March 1996 to include 888 numbers. Then we ran out of 888 numbers. So, the NANC (North American Numbering Council) responded by assigning 877 numbers to relieve the pressure. 877 numbers were introduced on April 4, 1998. 866 numbers were added in July 2000, and 855 in February 2001. See 800 Service for a full explanation.

880

The NANP (North American Numbering Plan) area codes 880, 881 and 882 were established to provide a means by which toll-free calling could be extended beyond the borders of the country in which the party paying for the resides. Rather and for example, the Caribbean caller pays for the international segment of the call to the U.S. gateway, and the called party pays for the domestic U.S. segment of the call. In theory, this concept can be implemented between any countries that share the NANP. However, they primarily are used to allow Caribbean callers to call the U.S.

881

See 880.

882

See 880.

888 Service

A North American toll-free area code. When North America was in danger of running out of 800 numbers, the 888 prefix was introduced in April 1996. When 888 numbers began to run out, 877 numbers were introduced in April 1998. Since that time, the 855 and 866 area codes also have been introduced. All of these toll-free area codes follow the numbering convention of 8NN, with the last two digits always the same. See 800 Service for a full explanation.

8B/10B Local Fiber

8-byte/10-byte local fiber. Fiber channel physical media that supports speeds up to 149.76 Mbps over multimode fiber.

8B6T

8 Bits 6 Tri-state symbols. A data encoding/decoding scheme that encodes eight data bits into a 6-bit transmission sequence. The six bits represented via a tri-state symbol comprising positive voltage, zero voltage, and negative voltage. This method of representing bits differs from the NRZ (Non Return to Zero) method used in 4B5B. 100Base-T4 is the only standard which uses 8B6T. Once the data are encoded into the 8B6T format, the 6T codes are demultiplexed across three wire pairs. See also 4B5B, 8B10B, 100Base-T4, and NRZ.

8B10B

8 Bits 10 Bits. A data encoding/decoding scheme that encodes eight data bits into a 10-bit transmission sequence. The eight bits of data to be transmitted over the serial (i.e., one bit at a time) line are converted into a 10-bit code group prior to transmission, with the extra two bits of "special characters " serving such signaling and control functions as indicating the start of the data frame, the end of the data frame, and the link configuration. The primary purpose for the additional bits in the transmission code is to improve the transmission characteristics of the serial link, ensuring that sufficient bit-level transmissions occur such that the receiver can recover a "clock" (i.e., can synchronize) from the data stream. This type of timing mechanism generically is known as CDR (Clock/Data Recovery). The additional bits also increase the likelihood that the receiver can detect bit errors. Further, some of the special characters are in the form of bit patterns known as "commas," which enable the receiver to accomplish word (i.e., byte) alignment with respect to the incoming bit stream. 8B10B is used in some implementations of Gigabit Ethernet (GbE, or GE), which is standardized as 802.3z, and is proposed for use in 10GbE (10 Gbps Ethernet), which being standardized as 802.3ae. See also 4B5B, 5B6B, 8B6T, 10GbE, and GE.

8NN

The present convention for future toll-free numbers is 8NN, with the last two digits always the same. See 800 Service.

8th-Floor Decision

Refers to the 8th floor at the Washington offices of the FCC, where the commissioner's offices and meeting rooms are located. Decisions made on the 8th floor sometimes have a profound effect on new communication services.

9-track

A standard for 1/2" magnetic tape designed for data storage. Its nine tracks hold a byte (eight bits) plus one parity bit in a row across the tape width-wise.

900 MHz

The radio spectrum used in narrowband Personal Communications Services (PCS).

900 Number Rule

A rule passed by the FTC (Federal Trade Commission) and which became effective November 1, 1993. The Rule requires that advertisements for 900 numbers contain certain disclosures, including information about the cost of the call. This information also must be included in an introductory message, or preamble, at the beginning of any 900-number program where the cost of the call could exceed $2.00. Any caller must be afforded the opportunity to hang up at the conclusion of the preamble, without incurring any cost for the call. The Rule also requires that all preambles state that individuals under the age of 18 must have the permission of a parent or guardian to complete the call. The 900 Number Rule has been very instrumental in reducing the level of 900-num- ber abuse.

900 Service

A generic and common (and not trademarked) term for AT&T's, MCI's, Sprint's and other long distance companies' 900 services. All these services have "900" as their "area code." Dialing a 900-number is free to the company or person receiving the call, but costs money to the person making the call. Here's the story: 900 service was introduced as the industry's "information service" area code. You'd dial 1-900-WEATHER, for example, and punch in some touchtones in response to prompts and you could hear the weather in Sydney, Australia or Paris , France, wherever you might be planning your next vacation. For this service, you'd be charged perhaps 75 to 95 cents a minute. And you'd get the bill as part of your normal monthly phone bill. That was the original idea. Then some people got the idea that 900 would make a wonderful porn number and they started advertising "Call 900-666-3333 and speak with Diana. She really wants you." And they started charging $5 a minute. When huge 900 call bills started appearing on people's bills, there was an outcry from many subscribers who wouldn't pay the bills. Some children called on their parents' phones. Employees made calls from work and the company's accountants went nuts. So the industry retreated from 900 porn. Then someone thought ” "Why not sell things through an 900 number?" We could sell a set of ginzu knives for just calling this 900 number. No messing with credit cards or checks. The bill goes straight on your phone bill. At about the same time someone thought that 900 numbers would be great for running sweepstakes. "Call up, register your name for a free trip with a racing car team to the Australian Indianapolis 500. Three lucky people will be chosen . The call will cost you only $2.75." So 900 services became a new type of gambling.

The long distance companies providing 900 services reacted predictably to some of the newer services. They clamped down on who they would sign up, which service and/or product you could, or could not sell. And, rather than charging "a piece of the action" as they did in the beginning, the long distance companies began to charge for them as if they were normal long distance calls: charge a set-up fee, a fee for carrying the call, a fee for collecting the money and a fee for the possibility of bad debts . There are variations on these themes.

The 900 service business is rife with stories of people who are alleged to have made millions overnight with innovative 900 numbers. Clearly enormous monies have been made ” especially in the beginning when there was novelty to 900 calls. The prognosis is that the 900 number business will grow, that it will mature and that the North American public will wake up to its various scams and discover real value in many of its services. For example, one of the author's " genuine value" and favorite 900 services is fax-back. Dial a 900 number, punch in some touchtone digits, hang up and within seconds your fax machine begins to churn out useful information.

In the summer of 1991, AT&T issued guidelines for its EXPRESS900 service. Those guidelines included:

• The predominant purpose of the calls does not include Entertainment, Children's Programming, Credit/Loan Information, Fulfillment, Political Fundraising, Games of Chance, Postcard Sweepstakes, Job Lines and Personal Lines.

• Every program must have a Preamble and Caller Grace Period, with notification to callers of the opportunity to hang up before charging begins.

• Sponsors may not route calls to any telecommunications equipment or arrangements which allow charging to begin before the caller realizes any value on the call, e.g., Automatic Call Distribution (ACD) with call queuing, or Caller Hold.

9001

ISO 9001 is a rigorous international quality standard covering a company's design, development, production, installation and service procedures. Compliance with the standard is of increasing significance for vendors trading in international markets, in particular in Europe where ISO 9001 registration is widely recognized as an indication of the integrity of a supplier's quality processes. ISO is the International Standards Organization in Paris.

902-928 MHz

A frequency range for use by, amongst other things, cordless phones. Such frequency offers much greater range than traditional cordless phones. Some new 900 MHz phones also use spread-spectrum technology to further increase range and call security. Previous cordless phones operated within the 46-49 MHz band. The 900 contains 50 channels for cordless telephone transmission. The 46-49 MHz band contains only 10.

911 Service

911 is an emergency reporting system whereby a caller can dial a common number ” 911 ” for all emergency services. The caller will be answered at a common answering location which will figure the nature of the emergency and dispatch the proper response teams . The first 911 service came on line in 1968. Here are the reasons why 911 benefits a community: Only one number for all emergency services. It's an easy number to remember. It's an easy number to dial. It's great for travelers and new residents. Calls are received by trained personnel. See also E-911, which stands for Enhanced 911 service and typically includes ANI (Automatic Number Identification) and ALI (Automatic Location Information). 911 service is sometimes called B-911 which stands for Basic 911 service. The first 911 service in the United States was in 1968 in Alabama. See also Basic 911, B-911 and E-911.

9145

A common term in the southern part of America for a customer service representative (i.e. a salesman ) of the local telephone company.

950

Local exchange used by some North American long-distance carriers to let their customers access their calling card and other services.

950-XXXX

The Feature Group B Carrier Identification Code (CIC). You would dial 950- XXXX (the last four digits are the CIC) if you wanted to place a paid call from a pay phone, and use a carrier other than the preselected carrier, who might overcharge you. You also would use 950-XXXX if you wanted to dial around your preselected carrier, and use another carrier that does not offer Feature Group D access (i.e., equal access) in your area. Feature Group D, which is more expensive, allows you to dial 101XXXX to achieve the same thing. See also 101XXXX, Feature Group B, and Feature Group D.

958

Dial 958 in New York City and a computer run by Nynex (now called Bell Atlantic) will tell you the phone number you're calling from. This is very useful. Imagine having a jack on your wall. You've lost track of which phone line it's connected to. Dial 958 and bingo! You know. Other phone companies have similar services but they often have different numbers. In some parts of Pennsylvania, the phone number is 958-4100.

976

A local information, pay-per-call phone exchange. An information service that lets callers listen to recorded messages such as sports scores or adult conversations, at higher rates than normal calls. Similar to 900 service but, numbers are locally assigned. In other words, two different customers could have the same 976 number in two LEC territories . The sponsor of the 976 service splits revenue with the phone service provider.

999

Great Britain's equivalent of the United States emergency number 911.

9PZDD

End User Port Cost Recovery Charge DID.

@

The character typically above the 2 on your keyboard. It's called the "at sign." In English, its biggest use is in two apples @ 50 cents each equals $1 total." But in computerese, its big use is in electronic mail addressing. It is used to separate the domain name and the user name in an Internet address and is pronounced "at." For example, Bill Gates' e-mail address is [e-mail]. It is pronounced "Bill G at Microsoft.com. A professor at Rome University, Giorgio Stabile, announced on July 2000 that the symbol @ has been found on a commercial trade paper of Venetian merchants, dated 1536. The symbol was a commercial trademark for an amphor, a weight unit. The @ is called, in Spanish, "arroba", from an Arab word, meaning quart, that which is exactly the measuring unit "amphora", widely used in Greek and Roman tradition.