An Ethernet standard that operates at 100 Mbps and uses STP cabling. Also called Fast Ethernet. Variations of 100BaseT are 100BaseTX and 100BaseFX.
An Ethernet standard that operates at 10 Mbps and uses small coaxial cable up to 200 meters long. Also called ThinNet.
An Ethernet standard that operates at 10 Mbps and uses thick coaxial cable up to 500 meters long. Also called ThickNet.
An Ethernet standard that operates at 10 Mbps and uses twisted-pair cabling rated CAT-3 or higher and an RJ-45 connector.
Third Generation: The ability to use your cell phone to browse the Web, stream music and video, play online games, use instant messaging and video conferencing.
IEEE specifications for wireless communication and data synchronization. Also known as Wi-Fi. Apple Computer's versions of 802.11b/g are called AirPort and AirPort Extreme.
access point: A device connected to a LAN that provides wireless communication so that computers, printers, and other wireless devices can communicate with devices on the LAN.
Automatic Private IP Address: An IP address in the address range 169.254.x.x, used by a computer when it cannot successfully lease an IP address from a DHCP server.
In relation to analog communication, the range of frequencies that a communications channel or cable can carry. In general use, the term refers to the volume of data that can travel on a bus or over a cable stated in bits per second (bps), kilobits per second (Kbps), or megabits per second (Mbps). Also called data throughput or line speed.
A standard for wireless communication and data synchronization between devices, developed by a group of electronics manufacturers and overseen by the Bluetooth Special Interest Group. Bluetooth uses the same frequency range as 802.11b, but does not have as wide a range.
A connector used with thin coaxial cable. Some BNC connectors are T-shaped and called T-connectors. One end of the T connects to the NIC, and the two other ends can connect to cables or end a bus formation with a terminator.
A transmission technique that carries more than one type of transmission on the same medium, such as cable modem or DSL.
A technology that uses cable TV lines for data transmission requiring a modem at each end. From the modem, a network cable connects to an NIC in the user's PC, or a USB cable connects to a USB port.
Category 5: A category of unshielded twisted pair cable. CAT-6 has less crosstalk than CAT-5 or CAT-5e.
A wireless network that is designed to cover a wide area and is made up of numerous cells, which are sometimes called radio cells.
classless subnet masks
A subnet mask that can have a mix of zeroes and ones in one octet such as 11111111.11111111.11110000.00000000, which can be written as 255.255.240.0.
An application that has two components. The client software requests data from the server software on the same or another computer.
A protocol such as UDP that does not require a connection before sending a packet and does not guarantee delivery. An example of a UDP transmission is streaming video over the Web. Also called a best-effort protocol.
In networking, a protocol that confirms that a good connection has been made before transmitting data to the other end. An example of a connection-oriented protocol is TCP.
A cable used to connect two PCs into the simplest network possible. Also used to connect two hubs.
The gateway a computer on a network will use to access another network unless it knows to specifically use another gateway for quicker access to that network.
Dynamic Host Configuration Protocol server: The server that manages dynamically assigned IP addresses to computers on a network when they first access the network.
A Windows 9x/Me and Windows NT/2000/XP utility that uses a modem and telephone line to connect to a network.
Domain Name System, or Domain Name Service: A distributed pool of information (called the name space) that keeps track of assigned domain names and their corresponding IP addresses, and the system that allows a host to locate information in the pool. Compare to WINS.
A computer that can find an IP address for another computer when only the domain name is known.
Digital Subscriber Line: A telephone line that carries digital data from end to end, and can be leased from the telephone company for individual use. Some DSL lines are rated at 5 Mbps, about 50 times faster than regular telephone lines.
dynamic IP address
An assigned IP address that is used for the current session only. When the session is terminated, the IP address is returned to the list of available addresses.
fiber optic cable
a cable that transmits signals as pulses of light over glass strands inside protected tubing.
File Transfer Protocol: The protocol used to transfer files over a TCP/IP network such that the file does not need to be converted to ASCII format before transferring it.
fully qualified domain name: A host name and a domain name such as jsmith.amazon.com. Sometimes loosely referred to as a domain name.
Global System for Mobile Communications: An open standard for cellular WANs and cell phones that uses digital communication of data and is accepted and used worldwide.
Communication between two devices whereby transmission takes place in only one direction at a time.
Hypertext Transfer Protocol Secure: A version of the HTTP protocol that includes data encryption for security.
Internet Message Access Protocol, version 4: Version 4 of the IMAP protocol, which is an e-mail protocol that has more functionality than its predecessor, POP. IMAP can archive messages in folders on the e-mail server and can allow the user to choose not to download attachments to messages.
Another name for an air card. It works like a cell phone to connect to a cellular WAN to give your computer Internet access. The device can be a USB device or can be a card that inserts into a PC Card slot or ExpressCard slot on a laptop.
Internet service provider: A commercial group that provides Internet access for a monthly fee. AOL, Earthlink, and CompuServe are large ISPs.
A 32-bit address consisting of four numbers separated by periods, used to uniquely identify a device on a network that uses TCP/IP protocols. The first numbers identify the network; the last numbers identify a host. An example of an IP address is 126.96.36.199
Local Area Network: A computer network that covers only a small area, usually within one building.
Media Access Control address: A 48-bit hardware address unique to each NIC card and assigned by the manufacturer. The address is often printed on the adapter as hexadecimal numbers. An example is 00 00 0C 08 2F 35. Also called a physical address, an adapter address, or a hardware address.
A process in which a message is sent by one host to multiple hosts, such as when a video conference is broadcast to several hosts on the Internet.
Multiple Input/Multiple Output: A technology used to increase speed and range on a wireless network.
Network Address Translation: A process that converts private IP addresses on a LAN to the proxy server's IP address before a data packet is sent over the Internet.
Network Basic Input/Output System: An API protocol used by some applications to communicate over a NetBEUI network. NetBIOS has largely been replaced by Windows Sockets over a TCP/IP network.
Network Interface Card: An expansion card that plugs into a computer's motherboard and provides a port on the back of the card to connect a PC to a network. Also called a network adapter.
Term for each of the four 8-bit numbers that make up an IP address. For example, the IP address 188.8.131.52 has four octets.
Segment of network data that also includes header, destination address, and trailer information that is sent as a unit. Also called data packet or datagram.
Personal Area Network: A network consisting of personal devices at close range such as a cell phone, PDA, and notebook computer in communication.
Packet Internet Groper: A Windows and Unix command used to troubleshoot network connections. It verifies that the host can communicate with another host on the network.
(1) As applied to services running on a computer, a number assigned to a process on a computer so that the process can be found by TCP/IP. Also called a port address or port number. (2) Another name for an I/O address. (3) A physical connector, usually at the back of a computer, that allows a cable from a peripheral device, such as a printer, mouse, or modem, to be attached.
Point-to-Point Protocol: A protocol that governs the methods for communicating via modems and dial-up telephone lines. The Windows Dial-up Networking utility uses PPP.
Simple Mail Transfer Protocol: The protocol used by e-mail clients and servers to send e-mail messages over the Internet. See POP and IMAP.
status light indicators
Most network cards also provide status light indicators near the RJ-45 port. Depending on the card, the lights might indicate the speed of transmission being used among those the card supports, connectivity, and activity.
a group of four numbers (dotted decimal numbers) that tell TCP/IP if a remote computer is on the same or a different network.
A device used to segment a network. It can decide which network segment is to receive a packet, on the basis of the packet's destination MAC address.
Transmission Control Protocol/Internet Protocol: The suite of protocols that supports communication on the Internet. TCP is responsible for error checking, and IP is responsible for routing.
The protocol is used by client/server applications to allow an administrator or other user to control a computer remotely.
User Datagram Protocol: A connectionless protocol that does not require a connection to send a packet and does not guarantee that the packet arrives at its destination. UDP is faster than TCP because TCP takes the time to make a connection and guarantee delivery
Virtual Private Network: works by using encrypted data packets between a private network and a computer somewhere on the Internet.
Wired Equivalent Privacy: A data encryption method used on wireless networks that uses either 64-bit or 128-bit encryption keys that are static keys, meaning the key does not change while the wireless network is in use.
WiFi Protected Access: A data encryption method for wireless networks that use the TKIP (Temporal Key Integrity Protocol) encryption method and the encryption keys are changed at set intervals while the wireless LAN is in use.