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Troubleshooting Wireless Networks
cable head-end
A cable head-end (or headend) is the facility at a local cable TV office that originates and communicates cable TV services and cable modem services to subscribers. Continue Reading
spatial division multiple access (SDMA)
Also see frequency division multiple access (FDMA) and time division multiple access (TDMA). Continue Reading
10BASE-F
10BASE-F, one of several physical media specified by IEEE 802.3, is the use of optical fiber in an Ethernet local area network (LAN). Continue Reading
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visitor-based networking (VBN)
Visitor-based networking (VBN) is the provision of high-speed Internet access for mobile PC users in need of temporary service in public places. Continue Reading
network interface unit (NIU or Network Interface Device)
A network interface unit (NIU) (sometimes called a network interface device) is a device that serves as a common interfacefor various other devices within a local area network (LAN), or as an interface to allow networked computers to connect to an ... Continue Reading
balun
A balun is a device that joins a balanced line (one that has two conductors, with equal currents in opposite directions, such as a twisted pair cable) to an unbalanced line (one that has just one conductor and a ground, such as a coaxial cable).Continue Reading
lambda switching (photonic switching, or wavelength switching)
Lambda switching (sometimes called photonic switching, or wavelength switching) is the technology used in optical networking to switch individual wavelengths of light onto separate paths for specific routing of information.Continue Reading
telephone jacks
In the U. S., telephone jacks are also known as registered jacks, sometimes described as RJ-XX, and are a series of telephone connection interfaces (receptacle and plug) that are registered with the U.S. Federal Communications Commission (FCC).Continue Reading
ETSI (European Telecommunications Standards Institute)
The European Telecommunications Standards Institute (ETSI) is a non-profit organization that establishes telecommunications standards for Europe.Continue Reading
D-channel
In the Integrated Services Digital Network (ISDN), the D-channel is the channel that carries control and signalling information.Continue Reading
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High-Speed Circuit-Switched Data (HSCSD)
High-Speed Circuit-Switched Data (HSCSD) is circuit-switched wireless data transmission for mobile users at data rates up to 38.4 Kbps, four times faster than the standard data rates of the Global System for Mobile (GSM) communication standard in ...Continue Reading
whois
whois is a program that will tell you the owner of any second-level domain name who has registered it with Verisign (or with Network Solutions, which was acquired by Verisign).Continue Reading
X server
An X server is a server of connections to X terminals in a distributed network that uses the X Window System.Continue Reading
root directory
In a computer file system that is organized as a hierarchy or tree, the root directory is the directory that includes all other directories.Continue Reading
10BASE-36
10BASE-36 is a type of physical cabling defined in the IEEE 802.3 (Ethernet) standard for broadband application.Continue Reading
DECT (Digital Enhanced Cordless Telecommunications)
Unlike the analog cordless phones you may have in your home, DECT (Digital Enhanced Cordless Telecommunications) is a digital wireless telephone technology that is expected to make cordless phones much more common in both businesses and homes in the...Continue Reading
Transmeta
Transmeta is a Silicon Valley start-up company known for its recruitment of high profile talent and its Crusoe chip, designed for mobile Internet computing.Continue Reading
well-known port numbers
The well-known port numbers are the port numbers that are reserved for assignment by the Internet Corporation for Assigned Names and Numbers (ICANN) for use by the application end points that communicate using the Internet's Transmission Control ...Continue Reading
10BASE-2
10BASE-2, one of several physical media specified by IEEE 802.3 for use in an Ethernet local area network (LAN), consists of Thinwire coaxial cable with a maximum segment length of 185 meters.Continue Reading
10BASE-5
10BASE-5, one of several physical media specified by IEEE 802.3 for use in an Ethernet local area network (LAN), consists of Thickwire coaxial cable with a maximum segment length of 500 meters.Continue Reading
DARPA (Defense Advanced Research Projects Agency)
DARPA (Defense Advanced Research Projects Agency) is the independent research branch of the U.S. Department of Defense that funded a project that in time was to lead to the creation of the Internet.Continue Reading
DOCSIS (Data Over Cable Service Interface Specifications)
Now known as CableLabs Certified Cable Modems, DOCSIS (Data Over Cable Service Interface Specifications) is a standard interface for cable modems, the devices that handle incoming and outgoing data signals between a cable TV operator and a personal ...Continue Reading
Primary Rate Interface (PRI)
In the Integrated Services Digital Network (ISDN), there are two levels of service: the Basic Rate Interface (BRI), intended for the home and small enterprise, and the Primary Rate Interface (PRI), for larger users.Continue Reading
symmetric communications
Compare asymmetric communications.Continue Reading
phase-shift keying (PSK)
Phase-shift keying (PSK) is a method of digital communication in which the phase of a transmitted signal is varied to convey information.Continue Reading
ACTA (America's Carriers Telecommunications Association)
ACTA (America's Carriers Telecommunications Association) is a lobbying organization for over 165 small long-distance telephone carrier companies.Continue Reading
softswitch
Softswitch (software switch) is a generic term for any open application program interface (API) software used to bridge a public switched telephone network (PSTN) and Voice over Internet Protocol (VOiP) by separating the call control functions of a ...Continue Reading
value-added network (VAN)
A value-added network (VAN) is a private network provider (sometimes called a turnkey communications line) that is hired by a company to facilitate electronic data interchange (EDI) or provide other network services.Continue Reading
small form factor (SFF)
Small form factor (SFF) refers to any of several physically compact connector designs that have been developed for use in fiber optic systems.Continue Reading
metropolitan area network (MAN)
A metropolitan area network (MAN) is a network that interconnects users with computer resources in a geographic area or region larger than that covered by even a large local area network (LAN) but smaller than the area covered by a wide area network...Continue Reading
small form-factor pluggable (SFP)
Small form-factor pluggable (SFP) is a specification for a new generation of optical modular transceivers.Continue Reading
infranet
The infranet is a proposed universal, public, packet-switched supplement to the Internet for businesses and high-demand private users that would provide guaranteed security, reliability, and quality of service (QoS).Continue Reading
hybrid fiber coaxial network (HFC network)
A hybrid fiber coaxial (HFC) network is a telecommunication technology in which optical fiber cable and coaxial cable are used in different portions of a network to carry broadband content (such as video, data, and voice).Continue Reading
moonbounce or Earth-Moon-Earth (EME)
Moonbounce, also called Earth-Moon-Earth (EME), is a form of wireless communication in which the moon is used as a passive satellite.Continue Reading
Basic Rate Interface (BRI)
In the Integrated Services Digital Network (ISDN), there are two levels of service: the Basic Rate Interface (BRI), intended for the home and small enterprise, and the Primary Rate Interface (PRI), for larger users.Continue Reading
gigahertz (GHz)
The gigahertz, abbreviated GHz, is a unit of alternating current (AC) or electromagnetic (EM) wave frequency equal to one thousand million hertz (1,000,000,000 Hz).Continue Reading
subnetwork
A subnetwork is a separately identifiable part of a larger network that typically represents a certain limited number of host computers, the hosts in a building or geographic area, or the hosts on an individual local area network.Continue Reading
Veronica
Veronica is a program that allowed you to search the files of the Internet's Gopher servers for a particular search string.Continue Reading
Home Phoneline Networking Alliance (HPNA)
The HPNA (Home Phoneline Networking Alliance) is an industry group that promotes standards for using existing phone lines and jacks to interconnect computers within a home.Continue Reading
ferrule
A ferrule (from Latin viriola, meaning little bracelet) is a ring or cap attached to an object to protect against damage, splitting, or wear.Continue Reading
egress
Egress (pronounced EE-grehs, from Latin egressus, or going out) is the act of going out of something.Continue Reading
U interface
In Integrated Services Digital Network (ISDN) Basic Rate Interface service, a U interface is the electrical interface for the single twisted pair wire connection from a local phone company (the central office) to a home or business.Continue Reading
V.xx
The V Series Recommendations from the ITU-TS are summarized in the table below.Continue Reading
vampire tap
A vampire tap is a connection to a coaxial cable in which a hole is drilled through the outer shield of the cable so that a clamp can be connected to the inner conductor of the cable.Continue Reading
OC-768
OC-768 is currently the fastest synchronous optical network (SONET) standard rate for data transmission on optical fiber as part of the broadband ISDN (BISDN).Continue Reading
T1 (T-1)
Also see the T-carrier system, of which the T1 is a part.Continue Reading
netsplit
In using an Internet Relay Chat (IRC) network, a netsplit is the loss of contact between two IRC servers.Continue Reading
media attachment unit (MAU)
MAU is also sometimes used as the abbreviation for the token ring network multistation access unit (MSAU).Continue Reading
local access and transport area (LATA)
LATA (local access and transport area) is a term in the U.S. for a geographic area covered by one or more local telephone companies, which are legally referred to as local exchange carriers (LECs).Continue Reading
EtherExpress
EtherExpress is a technology from Intel that is used in network server adapters (devices that attach the server to the network cable) for Ethernet-based local area networks (LANs).Continue Reading
iNet
An iNet (pronounced AI-neht) is any network that uses the Internet Protocol (IP).Continue Reading
text on nine keys (T9)
Text on nine keys (T9) is a system that lets fixed and mobile phone users send text messages by pressing a number key for each letter in the message -- effectively making a keyboard out of the nine numeric phone entry keys.Continue Reading
RS-232C
RS-232C is a long-established standard ("C" is the current version) that describes the physical interface and protocol for relatively low-speed serial data communication between computers and related devices.Continue Reading
fractional T1
A fractional T1 or T3 line is a T1 or T3 digital phone line in the North American T-carrier system that is leased to a customer at a fraction of its data-carrying capacity and at a correspondingly lower cost.Continue Reading
conductance
Conductance is an expression of the ease with which electric current flows through a substance.Continue Reading
triplecast
A triplecast (TM) is the simultaneous broadcast of a program on television, radio, and an Internet site or channel.Continue Reading
EPOC
EPOC is an operating system designed for small, portable computer-telephones with wireless access to phone and other information services.Continue Reading
brouter
A brouter (pronounced BRAU-tuhr or sometimes BEE-rau-tuhr) is a network bridge and a router combined in a single product.Continue Reading
home network
Using Mobile IP (Mobile Internet Protocol), the home network is where a mobile device has its permanent IP address.Continue Reading
Preboot Execution Environment (PXE)
The Preboot Execution Environment (PXE) is an industry standard client/server interface that allows networked computers that are not yet loaded with an operating system to be configured and booted remotely by an administrator.Continue Reading
repeater
In digital communication systems, a repeater is a device that receives a digital signal on an electromagnetic or optical transmission medium and regenerates the signal along the next leg of the medium.Continue Reading
multihomed
Multihomed describes a computer host that has multiple IP addresses to connected networks.Continue Reading
Point-to-Point Tunneling Protocol (PPTP)
Point-to-Point Tunneling Protocol (PPTP) is a protocol (set of communication rules) that allows corporations to extend their own corporate network through private "tunnels" over the public Internet.Continue Reading
plesiochronous
Plesiochronous (pronounced plee-see-AH-krun-us, from Greek plesos, meaning close, and chronos, meaning time) is an adjective that describes operations that are almost, but not quite, in synchronization - in other words, almost synchronous.Continue Reading
erbium amplifier
An erbium amplifier, also called optical amplifier or an erbium-doped fiber amplifier or EDFA, is an optical or IR repeater that amplifies a modulated laser beam directly, without opto-electronic and electro-optical conversion.Continue Reading
active network
An active network is a network in which the nodes are programmed to perform custom operations on the messages that pass through the node.Continue Reading
B-channel (bearer channel)
In the Integrated Services Digital Network (ISDN), the B-channel is the channel that carries the main data.Continue Reading
ARPA (Advanced Research Projects Agency)
An agency of the United States Department of Defense, ARPA (Advanced Research Projects Agency) underwrote development for the precursor of the Internet, known as ARPANET. Initially a modest network of four interconnected university computers, ...Continue Reading
X terminal
An X terminal is typically a diskless computer especially designed to provide a low-cost user interface for applications that run in a network X server as part of a distributed X Window System.Continue Reading
AUI (attachment unit interface)
The AUI (attachment unit interface) is the 15-pin physical connector interface between a computer's network interface card (NIC) and an Ethernet cable.Continue Reading
modem doubling
Modem doubling is an inexpensive way for a user who wants a fast Internet connection, but can only connect with an analog telephone line, to use two 56kbps modems to double their bandwidth.Continue Reading
SMDS (Switched Multimegabit Data Service)
SMDS (Switched Multimegabit Data Service) is a public, packet-switched service aimed at enterprises that need to exchange large amounts of data with other enterprises over the wide-area network on a nonconstant or "bursty" basis.Continue Reading
downloading
Downloading is the transmission of a file from one computer system to another, usually smaller computer system.Continue Reading
Dialed Number Identification Service (DNIS)
DNIS (Dialed Number Identification Service) is a telephone service that identifies for the receiver of a call the number that the caller dialed.Continue Reading
Wake on LAN
Wake on LAN is a technology that allows a network professional to remotely power on a computer or to wake it up from sleep mode.Continue Reading
LMDS (Local Multipoint Distribution System)
LMDS (Local Multipoint Distribution System) is a system for broadband microwave wireless transmission direct from a local antenna to homes and businesses within a line-of-sight radius, a solution to the so-called last-mile technology problem of ...Continue Reading
network terminator 1 (NT1)
Using the Integrated Services Digital Network (ISDN) Basic Rate Interchange (Basic Rate Interface in ISDN) service, an NT1 (network terminating unit is a device that accepts a two-wire signal from the phone company and converts it to a four-wire ...Continue Reading
downstream
This term should not be confused with downlink.Continue Reading
FRAD (frame relay access device or frame relay assembler/dissembler)
A FRAD (frame relay access device; also sometimes referred to as a frame relay assembler/dissembler) is a box that encapsulates (puts frame relay header and trailer information on) outgoing data packets and decapsulates (removes frame relay headers ...Continue Reading
Thinnet
Thicknet and Thinnet (sometimes called ThickWire and ThinWire) are commonly used terms for the larger and smaller size of coaxial cable used in Ethernet local area networks.Continue Reading
RNIS (Reseau Numerique a Integration de Services)
RNIS (Reseau Numerique a Integration de Services) is the European name for Integrated Services Digital Network (ISDN).Continue Reading
telecenter
A telecenter (US spelling) or telecentre (UK spelling) is a work location usually in a different place than the organization's main office that provides convenient occasional access for telecommuting to work equipment that they don't have at home or...Continue Reading
ECC (error correction code or error checking and correcting)
ECC (either "error correction [or correcting] code" or "error checking and correcting") allows data that is being read or transmitted to be checked for errors and, when necessary, corrected on the fly.Continue Reading
Mesh Connectivity Layer (MCL)
Mesh Connectivity Layer (MCL) is a technology that allows a computer user to connect to a wireless mesh network that uses Wi-Fi or WiMax. The wireless mesh network can be connected to the Internet through a single computer using a leased T-1 line ...Continue Reading
Aloha (Aloha method)
Aloha, also called the Aloha method, refers toa simple communications scheme in which each source (transmitter) in a network sends data wheneverthere is a frame to send.Continue Reading
virtual network adapter
A virtual network adapter is a program (instead of a physical network adapter) that allows a computer to connect to a network. A virtual network adapter can also be used to connect all the computers on a local area network (LAN) to a larger network ...Continue Reading
Crash Course: VLANs
These resources will provide you with all the information needed to understand VLANs, from what they are to what they do and how they do it.Continue Reading
Guide to network performance management
This guide introduces you to network management best practices and pitfalls to avoid, and provides troubleshooting help and advice for monitoring and maintaining your network for best performance.Continue Reading
daisy chain
A daisy chain is an interconnection of computer devices, peripherals, or network nodes in series, one after another. It is the computer equivalent of a series electrical circuit.Continue Reading
Advanced router configuration and management: Crash Course
Once you've mastered the basics, it's time to learn some of the more advanced features of the router. Check out these informative tips and indepth technical advice and take your router knowledge to the next level.Continue Reading
BNC (Bayonet Neil-Concelman or British Naval Connector)
A BNC (Bayonet Neil-Concelman, or sometimes British Naval Connector) connector is used to connect a computer to a coaxial cable in a 10BASE-2 Ethernet network. 10BASE-2 is a 10 MHz baseband network on a cable extending up to 185 meters - the 2 is a ...Continue Reading
pulse code modulation (PCM)
Pulse code modulation (PCM) is a digitalscheme for transmitting analogdata.Continue Reading
Network routers: Crash Course
Network routers make an enterprise network run. This crash course gives you all the router basics you need.Continue Reading
central office (CO)
In telephone communication in the United States, a central office (CO) is an office in a locality to which subscriber home and business lines are connected on what is called a local loop.Continue Reading
CATV (community access television)
CATV (originally "community antenna television," now often "community access television") is more commonly known as "cable TV." In addition to bringing television programs to those millions of people throughout the world who are connected to a ...Continue Reading
Routing protocol basics, part 1
A detailed look at the characteristics of IGP routing protocols RIP and IGRP/EIGRP.Continue Reading
Telecommunications Act of 1996
The Telecommunications Act of 1996, enacted by the U.S. Congress on February 1, 1996, and signed into law by President Bill Clinton on February 8, 1996, provided major changes in laws affecting cable TV, telecommunications, and the Internet.Continue Reading
soliton
A soliton is a special form of light pulse that can be transmitted over a fiber optic channel.Continue Reading
port 80
On a Web server or Hypertext Transfer Protocol daemon, port 80 is the port that the server "listens to" or expects to receive from a Web client, assuming that the default was taken when the server was configured or set up.Continue Reading
transit
Transit is the connection to and use of a telecommunication path provided by a vendor.Continue Reading