Network Protocols Explained

By Jim Campbell

Network protocols help computers communicate.
i network cable image by .shock from

A network protocol lays out the rules for data communication between computers. These set of rules allow network card manufacturers to create drivers that interface between network cables, hardware devices and the computer's operating system. Several network protocols are available, but the most common is TCP/IP, which is the "language" of the Internet. It's these protocols that send computer communication from the network card, transmit over the cables and find the right computer to deliver the data packets.


Network protocols are "layered." This means the rules laid out to send a data packet are segmented into several different parts. A protocol designer can create rules for each layer, so network card designers can use the protocol in different ways to make the transmission of data more efficient. It also allows network designers to adapt the protocol for a specific purpose such as Internet communications or small network workgroups with only a few clients.


Several network protocols exist, but TCP/IP has taken over as the most popular construct. TCP/IP is the language of the Internet, so companies and individuals incorporate it into the network topology. Other network protocols include IPX, which is a language developed by Novell. Apple has AppleTalk that allows Mac desktops to interact. Tokenring is an older technology used with coaxial cabling. It connected small networks together as well.


A network protocol is integrated into the topology using drivers created by hardware designers and operating system vendors. For instance, when a user installs Microsoft Windows, the operating system searches for a network card, and installs the TCP/IP protocol if one is found. This tells the operating system that TCP/IP is used to communicate over the network, and it allows Windows to "understand" incoming data packets.


A network can use more than one protocol on the same topology. This is called a "heterogeneous" environment. For instance, a large network may have Windows clients that use a Novell server to host email and shared files. The network uses TCP/IP between Windows clients and the Internet, and it has IPX installed to communicate with the Novell servers. The two protocols work simultaneously, and it is seamless to the user who browses the Internet and accesses the Novell servers.


Protocols only determine the path and rules necessary for computer communication. Security is not implemented unless the protocol transmits encrypted data. Firewalls are implemented on the network for that reason to block malicious attempts at gaining access to network resources. Users should install antivirus software to protect from spyware and other malware that steals personal information.