Internet Protocol
IP is the primary network protocol used on the Internet, developed in the 1970s. On the Internet and many other networks, IP is often used together with the Transport Control Protocol (TCP) and referred to interchangeably as TCP/IP.
IP supports unique addressing for computers on a network. Most networks use the IP version 4 (IPv4) standard that features IP addresses four bytes (32 bits) in length. The newer IP version 6 (IPv6) standard features addresses 16 bytes (128 bits) in length.
Kbps / kbps, Mbps, Gbps
One kilobit per second (Kbps) equals 1000 bits per second (bps). Kbps is also written as “kbps" that carries the same meaning. Likewise, one megabit per second (Mbps) equals one million bps and one Gigabit equals one billion bps.
Network performance is best measured in bps, but sometimes numbers are given in bytes per second (Bps). Then, one KBps equals one kilobyte per second, one MBps equals one megabyte per second, and GBps equals one gigabyte per second. Many times people write KBps, for example, when they mean Kbps, and it is important to be clear on this distinction.
LAN - Local Area Network
A local area network (LAN) supplies networking capability to a group of computers in close proximity to each other such as in an office building, a school, or a home. A LAN is useful for sharing resources like files, printers, games or other applications. A LAN in turn often connects to other LANs, and to the Internet or other WAN.
Most local area networks are built with relatively inexpensive hardware such as Ethernet cables, network adapters, and hubs. Wireless LAN and other more advanced LAN hardware options also exist.
Modem
Traditional modems used in dial-up networking convert data between the analogue form used on telephone lines and the digital form used on computers. Standard dial-up network modems transmit data at a maximum rate of 56,000 bits per second (56 Kbps). However, inherent limitations of the public telephone network limit modem speeds to 33.6 Kbps or lower in practice.
Broadband modems that are part of cable and DSL Internet service use more advanced signalling techniques to achieve dramatically higher network speeds than traditional modems. Broadband modems are sometimes called "digital modems" and those used for traditional dial-up networking, "analogue modems." Cellular modems that establish Internet connectivity through a digital cell phone also exist. A patch cable connects two network devices. Patch cables are typically CAT5 / CAT5e Ethernet cables linking a computer to a nearby network hub, switch or router.
Patch Cable
Ethernet patch cables are useful to those building home computer networks and also to travellers who need wired access to Internet connections such as those provided in hotel rooms. They are normally manufactured using stranded rather than solid sheathing in order to give them pliability that reduces risk of breakage when unplugging or carrying them.
A crossover cable is a specific type of Ethernet patch cable used to directly connect two computers to each other.
Fibre optic patch cables are also commonly used in the networking. The term patch cord is sometimes used synonymously with patch cable, although patch cords are often non-network types of cables such as those for wiring stereo components.
Also Known As: patch cord
RJ45
RJ45 is a standard type of connector for network cables. RJ45 connectors are most commonly seen with Ethernet cables and networks.
RJ45 connectors feature eight pins to which the wire strands of a cable interface electrically. Standard RJ-45 pinouts define the arrangement of the individual wires needed when attaching connectors to a cable.
Several other kinds of connectors closely resemble RJ45 and can be easily confused for each other. The RJ-11 connectors used with telephone cables, for example, are only slightly smaller (narrower) than RJ-45 connectors.
Also Known As: Registered Jack 45
Routers
Routers are physical devices that join multiple wired or wireless networks together. Technically, a wired or wireless router is a Layer 3 gateway, meaning that the wired/wireless router connects networks (as gateways do), and that the router operates at the network layer of the OSI model.
Home networkers often use an Internet Protocol (IP) wired or wireless router, IP being the most common OSI network layer protocol. An IP router such as a DSL or cable modem broadband router joins the home's local area network (LAN) to the wide-area network (WAN) of the Internet.
By maintaining configuration information in a piece of storage called the routing table, wired or wireless routers also have the ability to filter traffic, either incoming or outgoing, based on the IP addresses of senders and receivers. Some routers allow the home networker to update the routing table from a Web browser interface. Broadband routers combine the functions of a router with those of a network switch and a firewall in a single unit.
Server
A network server is a computer designed to process requests and deliver data to other (client) computers over a local network or the Internet.
Network servers typically are configured with additional processing, memory and storage capacity to handle the load of servicing clients. Common types of network servers include:
Web servers
Proxy servers
FTP servers
Online game servers
Numerous systems use this client / server networking model including Web sites and email services. An alternative model, peer-to-peer networking enables all computers to act as either a server or client as needed.
Switch
A network switch is a small hardware device that joins multiple computers together within one local area network (LAN). Technically, network switches operate at layer two (Data Link Layer) of the OSI model.
Network switches appear nearly identical to network hubs, but a switch generally contains more intelligence than a hub. Unlike hubs, network switches are capable of inspecting data packets as they are received, determining the source and destination device of each packet, and forwarding them appropriately. By delivering messages only to the connected device intended, a network switch conserves network bandwidth and offers generally better performance than a hub.
As with hubs, Ethernet implementations of network switches are the most common. Mainstream Ethernet network switches support either 10/100 Mbps Fast Ethernet or Gigabit Ethernet (10/100/1000) standards.
Different models of network switches support differing numbers of connected devices. Most consumer-grade network switches provide either four or eight connections for Ethernet devices. Switches can be connected to each other, a so-called daisy chaining method to add progressively larger number of devices to a LAN.
Telephony
The term telephony refers to the technology behind voice communications (typically, telephone networks). Telephony ordinarily involves analogue electrical signalling over copper wire. Newer IP telephony technology converts analogue voice into digital data packets to support telecommunication over Internet Protocol networks. So-called "voice over IP" (VoIP) solutions today support IP telephony.
The deployment of Internet telephony allows both voice and data to share the same networks. The telecommunications industry is moving toward this "convergence" for largely financial reasons. However, traditional telephone networks are extremely reliable, and IP telephony must first achieve a similar level of capability before it can completely replace older telephony systems.
USB
USB is a high-performance serial bus communication technology. Most new computers and associated peripheral devices like printers and scanners contain built-in support for this technology. USB hubs for file and printer sharing also exist. USB and FireWire are the most popular, competing standards for networking computer peripherals.
Using USB for Local Networking
To build a USB network, simply connect USB cables to the USB ports on those devices. USB is plug and play compatible, meaning the operating system USB driver software automatically detects and configures device connections. One USB network supports up to 127 devices. USB interfaces are backward compatible; for example, a USB 2.0 and a USB 1.1 can be networked. When two ends of a connection support different versions of USB, the link automatically runs at the lower speed of the older version.
USB Keys
As an alternative to using USB technology for local area networking, USB keys can be used to transfer files between two devices without requiring cables. To use a USB key (also known as a memory stick), copy files from one computer onto the key, then physically carry the stick to a different computer and copy the files onto that device.
Also Known As: Universal Serial Bus
VoIP
VoIP is a technology that allows telephone calls to be made over computer networks like the Internet. VoIP converts analogue voice signals into digital data packets and supports real-time, two-way transmission of conversations using Internet Protocol (IP).
VoIP calls can be made on the Internet using a VoIP service provider and standard computer audio systems. Alternatively, some service providers support VoIP through ordinary telephones that use special adapters to connect to a home computer network.
VoIP offers a substantial cost saving over traditional long distance telephone calls. The main disadvantage of VoIP is, like cell phones, a greater potential for dropped calls and generally lesser voice quality.
Also Known As: Voice over Internet Protocol (IP)
VPN
A VPN utilizes public telecommunications networks to conduct private data communications. Most VPN implementations use the Internet as the public infrastructure and a variety of specialized protocols to support private communications through the Internet.
VPN follows a client and server approach. VPN clients authenticate users, encrypt data, and otherwise manage sessions with VPN servers utilizing a technique called tunnelling.
VPN clients and VPN servers are typically used in these three scenarios:
To support remote access to an intranet
To support connections between multiple intranets within the same organization, and
To join networks between two organizations, forming an extranet
The main benefit of a VPN is the lower cost needed to support this technology compared to alternatives like traditional leased lines or remote access servers.
VPN servers can also connect directly to other VPN servers. A VPN server-to-server connection extends the intranet or extranet to span multiple networks.
Also Known As: virtual private network
WAN
A WAN spans a large geographic area, such as a state, province or country. WANs often connect multiple smaller networks, such as local area networks (LANs) or metro area networks (MANs). The world's most popular WAN is the Internet. Some segments of the Internet, like VPN-based extranets, are also WANs in themselves. Finally, many WANs are corporate or research networks that utilize leased lines.
WANs generally utilize different and much more expensive networking equipment than do LANs. Also Known As: wide area network
WAP - Wireless Access Points and Wireless Application Protocol
WAP - the Wireless Application Protocol - defines a network architecture for content delivery over wireless networks. Central to the design of WAP is a network stack based on the OSI model. WAP implements several new networking protocols that perform functions similar to the well-known Web protocols HTTP, TCP, and SSL.
The term "WAP" also is used to refer to wireless access points.
Wi-Fi - Wireless Fidelity
Wi-Fi is the industry name for wireless LAN (WLAN) communication technology related to the IEEE 802.11 family of wireless networking standards.