What Is a Network Protocol, and How Does It Work?

A network protocol is an established set of rules that determine how data is transmitted between different devices in the same network. Essentially, it allows connected devices to communicate with each other, regardless of any differences in their internal processes, structure or design. Network protocols are the reason you can easily communicate with people all over the world, and thus play a critical role in modern digital communications.

Similar to the way that speaking the same language simplifies communication between two people, network protocols make it possible for devices to interact with each other because of predetermined rules built into devices’ software and hardware. Neither local area networks (LAN) nor wide area networks (WAN) could function the way they do today without the use of network protocols.

How Network Protocols Work

Network protocols take large-scale processes and break them down into small, specific tasks or functions. This occurs at every level of the network, and each function must cooperate at each level to complete the larger task at hand. The term protocol
suite refers to a set of smaller network protocols working in conjunction with each other.

Network protocols are typically created according to industry standard by various networking or information technology organizations.

The following groups have defined and published different network protocols:

While network protocol models generally work in similar ways, each protocol is unique and operates in the specific way detailed by the organization that created it.

Who Uses Network Protocols?

Network protocols aren’t only relevant to certified network specialists or IT professionals. Billions of people use network protocols daily, whether they know
it or not.

Every time you use the internet, you leverage network protocols. Though you may not know how network protocols work or how frequently you encounter them, they are necessary for using the internet or digital communications in any capacity.

List of Network Protocols

There are thousands of different network protocols, but they all perform one of three primary actions:

Each type is necessary to use network devices swiftly and safely, and they work together to facilitate that usage.

Communication

Communication protocols allow different network devices to communicate with each other. They are used in both analog and digital communications and can be used for important processes, ranging from transferring files between devices to accessing the internet.

Common types of communication protocols include the following:

• Automation: These protocols are used to automate different processes in both commercial and personal settings, such as in smart buildings, cloud technology or self-driving vehicles.
• Instant messaging: Instantaneous, text-based communications on smartphones and computers occur because of a number of different instant messaging network protocols.
• Routing: Routing protocols permit communication between routers and other network devices. There are also routing protocols specifically for ad hoc networks.
• Bluetooth: Ever-popular Bluetooth devices — including headsets, smartphones and computers — work due to a variety of different Bluetooth protocols.
• File transfer: If you have ever moved files from one device to another, either via a physical or digital medium, you’ve used file transfer protocols (FTP).
• Internet Protocol: Internet Protocol (IP) allows data to be sent between devices via the internet. The internet could not operate as it currently does without IP.

Network Management

Network management protocols define and describe the various procedures needed to effectively operate a computer network. These protocols affect various devices on a single network — including computers, routers and servers — to ensure each
one, and the network as a whole, perform optimally.

The functions of network management protocols include the following:

• Connection: These protocols establish and maintain stable connections between different devices on the same network.
• Link aggregation: Link aggregation protocols allow you to combine multiple network connections into one link between two devices. This works to increase the strength of the connection and helps sustain the connection should one of the links fail.
• Troubleshooting: Troubleshooting protocols allow network administrators to identify errors affecting the network, evaluate the quality of the network connection, and determine how administrators can fix any issues.

Security

Security protocols, also called cryptographic protocols, work to ensure that the network and the data sent over it are protected from unauthorized users.

Common functions of security network protocols include the following:

• Encryption: Encryption protocols protect data and secure areas by requiring users to input a secret key or password in order to access that information.
• Entity Authentication: Entity authentication protocols create a system that requires different devices or users on a network to verify their identity before accessing secure areas.
• Transportation: Transportation security protocols protect data while it is transported from one network device to another.

Network Protocol Example

Whether you know it or not, you’ve absolutely encountered network protocols when using electronic devices – and some of them are readily identifiable.

Here are a few examples of the most commonly used network protocols:

• Hypertext Transfer Protocol (HTTP): This Internet Protocol defines how data is transmitted over the internet and determines how web servers and browsers should respond to commands. This protocol (or its secure counterpart, HTTPS)
  appears at the beginning of various URLs or web addresses online.
• Secure Socket Shell (SSH): This protocol provides secure access to a computer, even if it’s on an unsecured network. SSH is particularly useful for network administrators who need to manage different systems remotely.
• Short Message Service (SMS): This communications protocol was created to send and receive text messages over cellular networks. SMS refers exclusively to text-based messages. Pictures, videos or other media require Multimedia Messaging
  Service (MMS), an extension of the SMS protocol.

Network protocols do not simply define how devices and processes work; they define how devices and processes work together. Without these predetermined conventions and rules, the internet would lack the necessary infrastructure it needs to be functional
and useable. Network protocols are the foundation of modern communications, without which the digital world could not stand.

CompTIA Network+ covers computer networking topics including network protocols. Download the exam objectivesto see all the topics covered by this IT certification.

Read more about Computer Networks.