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Brad's Networking Terms Page
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10/100 Dual speed Network components that support devices based on both Ethernet (10 Mbps) and Fast Ethernet (100 Mbps) technologies. 10 BaseT A sub specification of IEEE 802.3 that requires the use of unshielded twisted pair telephone cabling with RJ-45 phone jacks to be used by Ethernet applications. The maximum length of a segment of twisted pair cable is 330 feet. 100BaseT The IEEE specifications for Fast Ethernet networks. 10Base2 coaxial cable The IEEE specifications for thin wire or thin net Ethernet network cable with a maximum segment length of 185 meters. 10Base5 coaxial cable The IEEE specifications for thick wire Ethernet network cable with a maximum segment length of 500 meters. 802.11 An IEEE specification for wireless networking in the 2.4GHz frequency range with a maximum 2Mbps data transfer rate. 802.11a An IEEE specification for wireless networking in the 5GHz frequency range with a maximum 54Mbps data transfer rate. The 802.11a specification also includes QoS (Quality of Service) technology to protect voice and multimedia data. At this time no 802.11a products are available on the market. IEEE 802.11b International standard networking technology for LAN wireless implementations that revised 802.11 to increase transmission speeds to 11Mbps. 802.11e A proposed IEEE specification that will include QoS (Quality of Service) features, particularly the ability to recognize and prioritize different types of data, and security provisions. The specification draft has not yet been ratified by the IEEE. IEEE 802.3 International standard networking technology for Ethernet implementations. Access point A wireless LAN transceiver that bridges a wired LAN to wireless devices. Active Hub Self-powered USB hubs that have their own power supply and are able to supply power to USB devices that require 100mA or more power. USB hubs without power supplies are referred to as passive hubs. Adapter An electronic card or that installs in a PC's PCI or ISA slot or plugs into a PC Card slot or USB port to expand the PC's functionality. AppleTalk Apple Computer's networking application for Macintosh computers. Asymmetric Digital Subscriber Line (ADSL) A version of digital subscriber line technology with a range of 18,000 feet that transmits over a single copper twisted pair cable at upstream rates of 16 to 640 Kbps and downstream rates of 1.5 to 9 Mbps. Attenuation A decrease in a signal's strength (measured in decibels) as it transmits over wires or cables. The shorter the wire or cable the less attenuation occurs. Backbone The centralized part of a large network that links two or more subnetworks and is the primary path for data transmission. Bandwidth The amount of transmission capacity that is available on a network at any point in time. Available bandwidth is dependent on factors such as the rate of data transmission speed between networked devices and the type of device used to connect PCs to a network. Baseband A transmission method in which digital signals are carried over the entire bandwidth of a transmission medium. Bidirectional The ability to transmit signals in two directions. Bits per second (bps) A measure of data transmission speeds over communication lines based on the number of bits that can be sent or received per second. Bluetooth wireless technology A technology specification for linking portable computers, personal digital assistants (PDAs), and mobile phones for short-range transmission of voice and data across a global radio frequency band without the need for cables or wires. Bluetooth is a frequency hopping technology in the 2.4GHz frequency spectrum, with a range of 30 feet. Bridge A device that links two local networks using the same communications protocol and allows them to interface with other networks as a single network. Broadband A data transmission system that supports analog and digital transmission of multiple voice, data, and video signals simultaneously over the bandwidth of a single medium at relatively high speeds. Bus A path inside a computer consisting of wires and other components for transmitting signals within a computer and among a computer and its peripherals. Bytes per second (Bps) A measure of data transmission speeds over communication lines based on the number of bytes that can be sent or received per second. Cable modem A modem that links a computer to a cable TV service for a 24/7 broadband Internet connection. Cable networking Linking computers and peripherals with bundled wires for the purpose of sharing resources. CardBus 32-bit standard for PC Card expansion devices. Combines support for legacy 16-bit Release 2.0 PC Cards and 32-bit PCI bus. Maximum throughput in burst mode transferring double-words (dwords) is 132MB/sec, or 66MB/sec in word mode, and 33MB/sec in byte mode. Requires Windows 98 or later operating system with limited support by Windows 95. Carrier Sense Multiple Access with Collision Detection (CSMA/CD) A method of managing traffic on an Ethernet network whereby a network device transmits data if it detects that a channel is available; if two devices transmit data simultaneously the sending devices detect a collision and retransmits after a random time delay. Category 3 or Cat3 Cable Twisted pair copper cables rated for low data rate networks such as 10Mbps Ethernet. Category 5 or Cat5 Cable Twisted pair copper cables rated for 10Mbps and 100Mbps date rates used for Fast Ethernet or 10/100 Ethernet. Category 5e or Cat5e Cable Twisted pair copper cables rated for 10Mbps, 100Mbps, and 1000Mbps (1Gbps) data rates. Category 7 or Cat7 Cable A proposed standard of twisted pair copper cables that with 600MHz frequency support (in contrast Cat5 and Cat5e each are 100MHz frequency standards). Client A networked PC that takes resources from a server and does not share its resources with other devices on the network. Coax See Coaxial cable. Coaxial cable Conductor used in Ethernet networks that is protected with shields of wire mesh and plastic insulation. Collision A CSMA/CD error condition that occurs when two computers transmit data simultaneously. Collision avoidance A network node characteristic for proactively detecting that it can transmit a signal without risking a collision. Communications protocol Hardware and software specifications for a network communication method. Convergence The evolution in networking whereby digital voice, data, and video are transmitted across networks within a common communications system. Cross-over cable Conductor for networking two computers without the use of a hub. Dial-up A communication connection via the standard telephone network or Plain Old Telephone Service (POTS). Digital Subscriber Line (DSL) Various protocols for high-speed data, voice, and video transmission over twisted-pair copper POTS telephone wires. Data-over-Cable Service Interface (DOCSIS) compliant In accordance with technical specifications for cable equipment used by both users and service providers. Domain Name System (DNS) A program that translates URLs to IP addresses by accessing a database maintained on a collection of Internet servers. The program works behind the scenes to facilitate surfing the Web with alpha versus numeric addresses. Downstream Data flowing on a network traffic path from a service provider to an end user. Dynamic Host Control Protocol (DHCP) A utility that enables a server to dynamically assign IP addresses from a predefined list and limit their time of use so that they can be reassigned. Ethernet International standard networking technology for wired implementations with a speed of 10 Mbps. EtherTalk Apple Computer's support for Ethernet on its AppleTalk networking application Fast Ethernet International standard networking technology for wired implementations with a speed of 100 Mbps. Firewall A system that secures a network and prevents network access by unauthorized users. FireWire The IEEE 1394 standard for input/output technology for connecting high speed multimedia peripherals to a PC. Forward Error Correction (FOE) A class of technologies for improving communications bandwidth by correcting data bit parity errors on the receiving side of a communications transaction rather than requiring retransmission of data from the sending side of the transaction. Acronym "FEC" also used to be common. Frame Relay An efficient WAN technology that transmits data in packets or envelopes in bursts at standard speeds of 56Kbps. Frequency A measure of radio waves in cycles per second. Gateway Hardware and software for connecting networks using different technologies, such as Ethernet and powerline networks. Gigabit One billion bits. 1 Gigabit Ethernet - There are two standards within the 1 Gigabit Ethernet specification: 802.3z standard 1000Base-X, which uses fiber optic media; and 802.3ab 1000Base-T, which uses twisted pair (copper) media. The maximum nominal data transfer rate is 1,000 megabits per second. Gigahertz (GHz) A measure of frequency in one billion cycles per second. Hertz (Hz) A measure of frequency in one cycle per second. High-bit Rate Digital Subscriber Line (HDSL) A version of digital subscriber line technology with a range of 12,000 feet that transmits over two twisted pair cables at a rate of 1.544 Mbps. Home network A home-based Local Area Network (LAN). Home Phoneline Networking Alliance (HomePNA) A networking industry group of companies working towards standardization of specifications for phoneline networking products and an expansion in market demand for such products. Home Radio Frequency Working Group (HRFWG) A networking industry group of companies working toward standardization of specifications for radio frequency networking products and an expansion in market demand for such products. HomePlug Powerline Alliance (HomePlug) A networking industry group of companies working toward standardization of specifications for powerline networking products and an expansion in market demand for such products. Hops Count A measure between two points on a network based on the number of adapter cards a transmission crosses. Hub A multi-port device used to connect PCs to a network. Each networked PC using Ethernet or Fast Ethernet is cabled to a hub, which can have 4,5,8,12,16, or 24 ports and can transmit data at either 10 Mbps or 100 Mbps or 10/100 dual speed. A hub transmits packets it receives to all ports. Hubs can be cabled together for network expansion. A hub's primary advantage is that its LEDs signal problems with any networked PC, while a network's operation is not impacted by problems on any one PC. Industry Standard Architecture (ISA) card An adapter that fits into an ISA slot of a PC motherboard. Industry Standard Architecture (ISA) slot An expansion bus for adapter cards used in PCs since the IBM AT model. ISA slots do not automatically assign IRQs to enable plug and play functionality. Infrared Data Association (IrDA) An international non-profit organization that develops and promotes technical standards for electronic data exchange between computing devices via wireless infrared light. Institute of Electrical and Electronic Engineers (IEEE) An international organization that sets electronic and electrical standards. Integrated Services Digital Network (ISDN) An ITU B64standard for bidirectional transmission of voice, data, and video signals over public or private telephone digital networks. International Telecommunications Union (ITU) A global organization whose mission is to adopt telecommunications treaties, regulations, and standards Internet appliance A computer that is intended primarily for Internet access via dial-up, cable, or network access. The devices are simple to set up and do not support installation of third-party software. They generally offer customized browsing, touch screen navigation, PIM applications and possibly PDA synchronization. Internet Protocol (IP) address A string of numbers assigned to each PC on a network. The IP address is used by the Internet Protocol to locate each device on the network. Internet Service Provider (ISP) A company that provides Internet access to individuals and businesses, either fee-based or for free. Internet Sharing Software (ISS) An application that allows all PCs on a network access the Internet simultaneously through a single modem and Internet Service Provider (ISP) account. IP Telephony Technology that supports voice, data, and video transmission via IP-based LANs, WANs, and the Internet. Voice Over IP is one technology protocol in the broader concept of IP Telephony. The promise and advantage of IP Telephony is that applications will be less media and location dependent as with Public Switched Telephone Network (PSTN) telephony. Jitter Signal distortion on an analog communication line. Kilobits per second (kbps) A measure of data transmission speed over communication lines in one thousand bits per second. Kilobytes per second (Kbps) A measure of data transmission speed over communication lines in one thousand bytes per second. Latency A measure of packet transmission time from the time a data transmission request is made by a device to the time the data is actually transmitted. Local Area Network (LAN) A system of connecting PCs and other devices within the same physical proximity for sharing resources, such as an Internet connections, printer, files, and drives. Mapping Assigning a PC to a shared drive or printer port on a network. Megabits per second (Mbps) A measure of data transmission speed over communication lines in one million bits per second. Megahertz (MHz) A measure of frequency in one million cycles per second. Modem A device that handles the modulation/demodulation process, i.e., from the sending device, digital computer signals are converted into analog signals that are transmitted over a phone line, and at the receiving point, analog signals are reconverted into digital signals. Multimedia Information that is simultaneously transmitted in multiple formats, including text, graphics, audio, and video Network access point Data exchange points for Internet Service Providers. Network adapter See Network Interface Card (NIC). Network Address Translator (NAT) A network capability that allows for the dynamic reuse of a single IP address for all PCs on a network. Network architecture The components and design of a network. Network Interface Card (NIC) A type of PC adapter card that attaches to a network cable to provide two-way communication between the computer and network devices, such as a hub or switch. NICs can operate at 10 Mbps (Ethernet) or 100 Mbps (Fast Ethernet) or 10/100 Mbps dual speed. Network operating system (NOS) The software that runs on a network server to control network functions. Noise Unneeded network signals that degrade network performance. Open Systems Interconnect Reference Model (OSI) An International Standards Organization network model based on seven integrated layers of communication standards for computers in a network. Packet A segment of data sent over a network whose size and format is governed by the communications protocol used. PC Card A removable expansion card that fits into a PCMCIA standard slot – primarily used in portable devices, particularly notebook computers and PDAs. PC Card peripherals include memory cards, modems, NICs, hard drives, and interface adapters. All PC Cards are 85.6mm long and 54.0mm wide. Three types of PC Cards include Type I (3.3mm thick), Type II (5.0mm thick), and Type III (10.5mm thick). Release 1.0 cards supported memory devices only, release 2.0 supported memory and I/O. The original PCMCIA PC Cards were 16-bit devices with a maximum throughput of 20MBps for memory transfers and 7.84MBps for I/O transfers, both in word mode. 32-bit CardBus PC Cards have a 132MB/sec maximum burst transfer rate in double-word mode. Personal Computer Memory Card International Association (PCMCIA) Personal Computer Memory Card International Association. A standards organization that defines the specifications for and promotes PC Card technology. Expansion cards now referred to as "PC Cards" were originally called "PCMCIA Cards." Passive Hub USB hubs that do not have their own power supply and are not sufficient to power USB devices that require more than 100mA. Peer-to-peer network A computer network that has no server. All networked PCs are equally able to act as a network server or clients. Peripheral Component Interconnect (PCI) card An adapter that fits into a PCI slot in a PC motherboard. Peripheral Component Interconnect (PCI) slot A high speed expansion bus for adapter cards developed by Intel and incorporated in Pentium computers. One advantage of PCI slots is that they automatically assign IRQs to enable plug and play functionality. Plug and Play(PnP) A computer system feature that provides for automatic configuration of add-ons. POTS Plain old telephone service, I.e., standard analog telephone service. Proxy server A server that prevents direct communication between two or more networks but forwards alllowable data requests to remote servers and/or responds to data requests directly from stored remote server data. Public Switched Telephone Network (PSTN) The global public telephone network. Redirection A networking application function that intercepts and reroutes input and output requests for networked devices. Residential Home-based. Residential Gateway A device that enables Internet access sharing by multiple PCs and other devices on a home network. RJ-11 connector A phone line connector used to connect a phone to a phone jack, to connect computers to a home phone line, and a modem to a phone line. RJ-45 connector An eight-pin serial connector for Ethernet cables that is slightly wider than a RJ-11 connector. Router A type of bridge that can link networks using different protocols and can link local and remote networks. Scalable A network characteristic related to its ability to expand and contract based on revised requirements. Server A PC that provides its resources to other PCs on a network. A dedicated server only provides resources; if its resources are used directly then it also functions as a client. Shared bandwidth The division of network transmission capacity among multiple networked devices. ShareWave Home networking wireless technologies that are an extension of the 802.11b standard and are optimized for multimedia content. Shielded twisted pair cable A casing containing one or more pairs of copper wires that are wrapped around each other that is used as a network communications transmission medium. Single-line Digital Subscriber Line (SDSL) A version of digital subscriber line technology with a range of 10,000 feet that transmits over a single copper twisted pair cable at a rate of 1.544 Mbps. Streaming digital audio Sound that is transmitted in a fashion so that it is received in a format that retains the order in which it was sent and therefore it can be played from the time the transmission initializes. Streaming digital video Moving images that are transmitted in a fashion that they are received in a format that retains the order in which they were sent and therefore can be played from the time the transmission initializes. Subnetwork A network segment that is created to simplify addressing and is connected to the central network through a router, hub, or gateway. Shared Wireless Access Protocol (SWAP) standard HomeRF standard for voice and data transmissions in the 2.4 GHz band of the Public Switched Telephone Network and the Internet to provide a range to cover a typical home and yard. Switch A type of hub that efficiently controls the way multiple devices use the same bandwidth so that each can operate at full bandwidth resulting in faster performance than with a hub. Rather than transmitting packets it receives to all ports as with a hub, a switch transmits packets to only the receiving port. TCP/IP Transmission Control Protocol/Internet Protocol. The standard Internet communication protocol. Telephony The conversion of audio to electrical signals that are transmitted over copper wire or radio waves. With respect to the Interet, services that use computer networks to transmit voice with data. Throughput The speed at which data travels through a network. Token Ring A network architecture where one data packet at a time is passed around a loop in one direction until it connects with its receiving computer. Transceiver A component of a Network Interface Card (NIC) that connects the card to a network cable and enables the two-way transmission of network signals. UNIX The operating system developed by AT&T Bell Laboratories that is used for the Internet infrastructure and many server applications. Linux and BSD Unix are derivatives, as are many other versions. Unshielded twisted pair (UTP) cable A wire transmission medium used in 10BaseT networks that is protected with light plastic versus heavy metal and is therefore prone to interference. Uplink port A connector on a LAN hub to link a hub or a subnetwork to a port on a second hub. Some hubs have a separate port for uplinking; others have a single port that can be switched between a single device port or an uplink port. Upstream Data flowing on a network traffic path from an end user to a service provider. USB (Universal Serial Bus) A connection between a PC and peripheral delivering high-speed bidirectional serial data transmission at the rate of 12 megabits per second. V.90 Protocol for dial-up modems that supports nominal 56K transfer speeds. In reality the maximum transfer speed limits are 53K for downloading and 33.6K for uploading. V.92 Protocol for dial-up modems that supports nominal 56K transfer speeds and manual adjustments for downloading and uploading speeds that exceed those of the v.90 dial-up modem protocol. Very High Data Rate Digital Subscriber Line (VDSL) A version of digital subscriber line technology with a range of 1,000 to 4,500 feet that transmits over a single copper twisted pair cable at upstream rates of 1.5 to 2.3 Mbps and downstream rates of 13 to 52 Mbps. Virtual Private Network (VPN) A data network created by companies using the Internet with secured protocols to preclude unauthorized access. Voice over IP Voice transmission in digital packets over the Internet, which is less expensive than voice transmission in analog packets using POTS. WebCam A Web page that displays still images or video that is captured by a digital camera connected to a PC. Wide Area Network (WAN) A communication system of connecting PCs and other devices across a large local, regional, national, or international geographic area. Wi-Fi Wireless-Fidelity. A designation by the Wireless Ethernet Compatibility Alliance ( WECA) that an 802.11b wireless network component meets the compatibility standard set for interoperability with other 802.11b products. |
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