Communication Protocol

What Does Communication Protocol Mean?

Communication protocols are formal descriptions of digital message formats and rules. They are required to exchange messages in or between computing systems. Communication protocols are important in telecommunications systems and other systems because they create consistency and universality for the sending and receiving of messages.


Communications protocols can cover authentication, error detection and correction, and signaling. They can also describe the syntax, semantics, and synchronization of analog and digital communications.

Communications protocols are implemented in hardware and software. There are thousands of communications protocols that are used everywhere in analog and digital communications. Computer networks cannot exist without them.

Techopedia Explains Communication Protocol

Before successful transmission can take place, networked communications devices have to agree on many physical aspects of the data that is to be exchanged. Rules defining data transmissions are called “protocols.”

There are many properties of a transmission that a protocol can define. For example, properties addressed with protocols may include:

  • Packet size.
  • Transmission speed.
  • Error correction types.
  • Handshaking and synchronization techniques.
  • Address mapping.
  • Acknowledgment processes.
  • Flow control.
  • Packet sequence controls.
  • Routing.
  • Address formatting.

Popular protocols include: File Transfer Protocol (FTP), TCP/IP, User Datagram Protocol (UDP), Hypertext Transfer Protocol (HTTP), Post Office Protocol (POP3), Internet Message Access Protocol (IMAP), Simple Mail Transfer Protocol (SMTP).

More About Communications Protocols

In a largely unregulated digital environment, communications protocols create rules.

For example, on the Internet, the types of communications protocols created by groups like the World Wide Web Consortium or W3C and the Internet engineering task force or IETF help to provide universal operations and limit various kinds of liability and vulnerabilities in these technologies.

One good example is authentication protocols. The authentication protocols work against things like distributed denial of service (DDoS) attacks and other common methods by which errant hackers can hobble vast networks or compromise or confuse network traffic.

When HTTP becomes HTTPS or the widespread use of SSL certificates becomes the norm, this is what’s intended by those establishing those types of communications protocols. The protocols work to “harden” systems against various kinds of abuse inherently, and that’s a big part of their value.

Other communications protocols govern the use of data packets in global network trajectories, which for its part sometimes resembles particle physics. It’s not like an open faucet where you just have a free stream of information flowing from one point to another.

Between the sender and receiver, the message consists of granular, discrete units, where each individual data packet has its own header, core information and routing trajectory. All of this has to be synchronized and choreographed in detailed ways, and that’s where communications protocols have such a powerful reach and such an important role.

In addition, the communication protocols that are used depend on the underlying technology itself. So as the technology advances, so do the protocols. That’s why you’ll see Internet protocols evolving into successive versions of themselves, and why we’ll likely see much different communication protocols in tomorrow’s advancing networks.

The Internet of Things promises to drive demand for new evolving communications protocols as ever wider sets of devices get connected to a global network.


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Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.