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| "Technology Services for Multi-Family Housing" | |
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| | | GLOSSARY OF TERMS 10base-T: IEEE specification for unshielded twisted pair cabling for Ethernet local area networks which transmit at 10 million bits per second. The distance limitation on 10 base-T networks is 100 meters. 100base-T: A proposed standard, compatible with 10base-T for transmitting at 100 Megabits over twisted pair cabling on local area networks. ADSL, Asymmetric Digital Subscriber Line: Modem that employs a very sophisticated coding scheme. This coding scheme permits transmission over copper pairs at rates as high as 6 Mbps for distances of 9,000 to 12,000 feet. Speeds of this magnitude bring to mind television signals; a 6 Mbps channel can easily handle a television movie. ANI, Automatic Number Identification: The business or residential customer's billing number. Customers such as call centers pay for callers' ANI to be sent to them simultaneously with incoming 800 and 888 calls. Backbone: A central high speed network that is used to connect smaller, independent networks. Bandwidth: The measure of the capacity of a communications channel. Analog telephone lines measure capacity in hertz, the difference in the highest and lowest frequency of the channel. Digital channels measure bandwidth in bits per second. BPS, Bits Per Second: The number of bits passing a point every second. The rate of transmission for digital signals. Bridge: A device used to connect LANs by forwarding packets across connections at the media access control (MAC) layer. Broadband: A data transmission scheme where multiple transmissions share a communication path. Cable television uses broadband transmission techniques. Data transmissions of voice, data and video signals over a single medium at high speeds. Cable Modem: Modem designed for use with coaxial cable circuit. Campus Network: A local network between floors of a building or between buildings of close proximity. Usually runs are short distance and without public access. Category 3 Cable: Rated for 10 mbps data transmission. Available in shielded twisted pair (STP) and unshielded twisted pair (UTP). Category 5 Cable: Rated for 100 Mbps data transmission. Available in shields twisted pair (STP) and unshielded twisted pair (UTP). CLEC, Competitive Local Exchange Carrier: A competitor to local telephone companies that has been granted permission by the state regulatory commission to offer local telephone service. CLECs compete with the Bell or independent telephone company. CLECs are also called ALECs, alternative local exchange carriers or simply local telephone companies. CO, Central Office: A local telephone company switch that routes telephone calls. End offices are central offices that connect end-users to the public network. Coaxial Cable: Single stand of copper running down the axis of the cable. This strand is separated from the outer shielding by an insulator made of foam or other dielectrics. Covering the cable is a conductive shield. Usually an outer insulating cover is applied to the overall cable - this has nothing to do with the carrying capacity of the cable. Because of the construction of the cable, obviously "coaxial" in nature, very high frequencies can be carried without leaking out. In fact, dozens of TV channels, each 6 MHz wide, can be carried on a single cable. Compression: Algorithm to reduce the size of the data, voice or video file to compact the file size, thus, reducing storage and transfer capacities CPE, Customer Premises Equipment: Terminating equipment supplied by carrier for use at customer site ie. modems, phones, routers. Data Speed: Expressed in bits per second (bps). The maximum rate at which data can reliably be transmitted over a delivery medium such as cable or fiber optic. Dedicated Circuits: Telecommunications lines reserved along predetermined routes for specific customers usually in a point to point configuration. DHCP, Dynamic Host Configuration Protocol: Provides mechanism for allocating IP addresses dynamically so that address can be reused when hosts no longer need them. DNS, Domain Name System: Refers to the names and IP addressed on Internet domain servers. Downstream: The direction of data returned from the Central Office back toward the user. Usually used with transmission speed (i.e. 1.5 Mbps downstream). DS-0, Digital Signal Level 0: The digital signals level 0 is 64 thousand bits per second. It refers to one channel of a T-1, E-1, T-3, fractional T-1 or fractional T-3 circuit. DS-1, Digital Signal Level 1: The T-1 transmission rate of 1.54 million bits per second. There are 24 channels associated with DS-1 or T-1 DS-3, Digital Signal Level 3: Refers to the T-3 transmission rate of 44 million bits per second with 672 channels. (T-3 is equivalent to 28 T-1s.) DSL, Digital Subscriber Line: Technology that combines two way voice and data transmissions at very high speeds over normal phone lines. See DSL types for more info. DSLAM, Digital Subscriber Line Access Multiplexer: Equipment used in the Central Office or Intranet to concentrate local users onto a fiber backbone. Ethernet: A local area network protocol defined by the IEEE 802.3. It defines how data is transmitted on and retrieved from local area computer networks. Fiber-optic cable: A type of cable made from glass rather than copper. The key advantage of fiber-optic cabling is that it is non-electric. Thus it is immune from electrical interference and interference from other cables within the same conduit. Fiber- optic cabling can be used for higher-speed transmissions than twisted pair copper cabling. Fractional T-1: Fractional T-1 lines are cheaper and have a fraction of the 24 channel capacity of T-1 lines. The most common capacities are: 2 channels = 128 kilobits; 4 channels = 256 kilobits and 6 channels = 384 kilobits. Fractional T-3: Fractional T-3 lines have a fraction of the 672 channel capacity of T-3 lines. For example, they might have the capacity of six T-1s or 144 channels. Fraction T-3s are cheaper than a full T-3 line. Frame relay: Frame relay networks are public data networks commonly used for local area network to local area network communications. Customers connect to frame relay services over telephone lines from each of their locations to the frame relay network. Frame relay services require less maintenance, hardware and upkeep than traditional data communications services for customers with more than about four locations. Gbps, Giga Bits Per Second: 1,000,000,000 (one billion) bits per second, a measure of telecommunications speed. A thousand Megabits. HDSL, High Bit Rate Digital Subscriber Line: see DSL types for full definition. High speeds technology utilizing existing phone lines to transmit data. Typical speeds are from 144 Kbps to over 8 Mbps currently. Homepage: A homepage is the default first page of a World Wide Web location that users see when they visit an organization's Web site. Hub: Each device such as computers and printers on a local area network is wired to the hub, generally located in the wiring closet. Hubs enable local area networks to use twisted pair cabling rather than more expensive, harder to install and move coaxial cabling. Hubs are sometimes referred to as concentrators. ILEC, Incumbent Local Exchange Carrier: ILECs refer to the Bell and independent telephone companies that sell local telephone service. This term differentiates telephone companies that were the providers of telephone service prior to the Telecommunications Act of 1996 and new competitors such as MSF, Teleport, MCI and AT&T. Internet: A series of interconnected local, regional, national and international networks, linked using TCP/IP. Internet links many government, university and research sites. It provides E-mail, remote login and file transfer services. IP, Internet Protocol: A uniquely assigned numeric address for each computer connected to the Internet. ISDN, Integrated Services Digital Network: Public circuit switched network that combines voice and data into a single medium. Usually runs at 64K or 128K, predecessor to DSL technology. ISP, Internet Service Provider: An Internet Service Provider connects end-users to the Internet via telephone lines. The ISP has banks of modems and devices such as ISDN interfaces for its own customers to dial into. The ISP then rents telephone lines to the Internet from its own location. Some Internet Service Providers such as UUNet also own Internet backbone networks. IXC, Inter Exchange Carrier: All telecommunications companies who provide long distance service, aka Common Carriers. Kbps, Kilo Bits Per Second: A measure of time relating to telecommunications speeds. One kilobit is 1.00 bits of information, the higher the number the faster the transmission speed. LAN, Local Area Network: A local area network is located on an individual organization's premise. It enables computer devices such as personal computers, printers, alarm systems and scanners to communicate with each other. Moreover, LANs allows multiple devices to share and have access to expensive peripherals such as printers, fax service, modem servers and centralized databases. LATA, Local Access Transport Area: At divestiture in 1984, LATAs were set up as the areas in which Bell telephone companies were allowed to sell local telephone services. LATAs cover metropolitan statistical areas based on population sizes. For example, Massachusetts has two LATAs and Wisconsin has four LATAs but Wyoming, which has a small population, has one LATA. The rules of divestiture decreed that long distance telephone companies such as AT&T, Sprint and MCI were allowed to carry calls between LATAs but the Bell telephone companies such as Illinois Bell could carry calls only within a LATA. Leased Line: A leased line is analogous to two tin cans and a string between two or more sites. Organizations that rent leased lines pay a fixed monthly fee for the leased lines that are available exclusively to the organization that leases them. Leased lines can be used to transmit voice, data, or video. They are also called private and dedicated lines. LEC, Local Exchange Carrier: Any company authorized by the state public utility commission to sell local telephone service. Local Loop: The local loop is the telephone line that runs from the local telephone company to the end user's premise. The local loop can be made up of fiber, copper or wireless media. MAN, Metropolitan Area Network: A metropolitan area network is a network that covers a metropolitan area such as a portion of a city. Hospitals, universities, municipalities and large corporations often have telephone lines running between sites within a city or suburban area. Mbps, Megabits Per Second: A transmission speed at the rate of millions of bits in one second. Digital telephone lines measure their capacity or bandwidth in bits per second. MIBS, Management Information Bases: A collection of network operational information residing in a virtual store that may be accessed, typically through an SNMP compliant system, for analysis. Modem: An antique electronic device that was used to modulate or change your computers digital output to an analog form for transmission over separate, dedicated phone lines. NIC, Network Interface Card: The hardware that handles the protocol conversion between your computer and connected network. Used in DSL service to talk to router. OS, Operations System: Software used to control the functionality and customization of a single computer or network. Examples are Linux, Win 98, Win NT. PBX, Private Branch Exchange: PBXs are computerized on site telephone systems located at commercial and non-profit organizations' premises. They route calls both within an organization, and from the outside world to people within the organization. Physical Labor: Products for the transmission of data through a communications channel by defining the electrical, mechanical and procedural specifications for IEEE 802 local area networks. POP, Point Of Presence: Location at which to gain accesses to a public or private network. POT, Plain Old Telephone Lines: Telephone lines connected to most residential and small business users. POTs lines are analog from the end user to the nearest local telephone company equipment. People using POTs service for data communications with modems are limited in the speed at which they can transmit data. RADSL, Rate Adaptive DSL: see DSL types for more info. RBOC, Regional Bell Operating Companies: The five companies created after the breakup of AT&T; Bell Atlantic, Bell South, Ameritech, Southwestern Bell, and US West. SDSL, Symmetric Digital Subscriber Line: See DSL types for more info. Server: A server is a specialized shared computer on the local area network with corporate files such as electronic mail. It can also be used to handle sharing of printers, fax machines and group modems. SHMP, Simple Network Management protocol: The network management protocol that defines the transfer of LAN operational data between management information bases (MIBS). T1: Digital transmission at 1.544Mbps. T1 is the most common transmission technique used in North America. T3: Digital transmission at 45Mbps. Basically 30 T1 circuits. Twisted Pair: Cable of two 18 to 24 gauge solid copper stands twisted around each other. The twisting helps protect against electromagnetism and Radio Frequency Interference (RFI). Upstream: Refers to transmission speed from user to the Internet. Opposite of Downstream. VDSL, Very High Bit Rate Digital Subscriber Line: See DSL types for more info. VPN, Virtual Private Network: A network service that is provided over a public network that is secure and works like a private network. WAN, Wide Area Network: A network with devices over a wide geographical area. WWW, World Wide Web: The World Wide Web has both multimedia capabilities. It links users form one network to another when they "click" on highlighted text. It was developed in 1989 to make information on the Internet more accessible. XDSL: Refers to all variations for the DSL family or technologies. 802.11: The IEEE standard that specifies a carrier sense media access control and physical layer specifications for wired and wireless LANs. | | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
