INTERNET PROTOCOL BASICs

The Internet Protocol (or IP) is the main computing protocol that allows for the communication of data across a network. Using this protocol, computers can deliver "packets," or units of data, to other computers and devices based on their unique IP addresses. It is the standard used by home and business computers, routers, browsers, and all networking software, and is the foundation of the Internet Protocol Suite.

Protocols Defined

1. At its most basic, a protocol is a set of rules that enables two computers to talk to each other. It's a computing standard that defines the syntax and regulations of a connection across a network: how to detect the other computer, how to send a message to it, how to format that message, and so on.

Internet Protocol Addresses

2. The Internet Protocol uses unique addresses, simply called IP addresses, in order to identify two computers or devices in a network. There are two standards of IP addresses. The most common is IPv4 (IP Address Version 4), which consists of four bytes, each represented by a value between 0 and 255, and each value separated by a period: 127.0.0.1, for example. A newer standard, IPv6, has also emerged; it consists of 16 bytes, resulting in longer addresses and more possibilities for variation. Every networked computer is assigned an IP address, although often modems can change IP addresses dynamically.

The Internet Protocol Suite

3. The Internet Protocol Suite is a set of protocols used in combination for different networking tasks. The Internet Protocol and the Transmission Control Protocol (TCP) are the two underlying protocols that all other protocols utilize, so the suite is commonly referred to as TCP/IP. While the Internet Protocol handles each transmission of each packet of data, the TCP is like an overseer, organizing data into packets and sending them to the IP, and on the flip side, rebuilding files from the individual packets the IP sent.

Layers of the Internet Protocol Suite

4. The Internet Protocol Suite is divided into four "layers" of communication: from bottom to top, there is the Data Link Layer, the Internet (or Network) Layer, the Transport Layer, and the Application Layer. Occasionally, the actual hardware involved is referred to as a bottommost fifth layer, called the Physical Layer. Very simply, the Link Layer links the computers, the Internet Layer allows the IP to transfer packets across the link, the Transport Layer uses the TCP to organize the packets, and the Application Layer consists of protocols for specific types of transferring.

Application Layer Protocols

5. While the Internet Protocol itself is the foundation for network communication, many other protocols you may recognize exist in the topmost Application Layer. These include HTTP (HyperText Transfer Protocol, which allows Web users to request websites from remote servers), FTP (File Transfer Protocol, which allows for the rapid transfer of files across the web), and POP3 and SMTP (Post Office Protocol 3 and Simple Mail Transfer Protocol, two protocols for sending and receiving e-mail).