Protocols Made Simple: Why Your Devices Can Talk to Each Other
We use so much technology today that we seldom think about it. Email comes in, you surf the web, you make a purchase and pay with a credit card at a website, and you watch a video on your phone, tablet, computer, or television. These are all very different technologies, and yet they all seem to communicate with different kinds of devices. What makes that possible? Protocols. Protocols are invisible agreements, sets of rules that allow computing devices (and let’s be clear, phones and televisions have become computing devices) to exchange information. We can think of protocols like “rules of the road” we use when we drive, or like good manners that make us all feel at ease.
Why Protocols Matter
Without protocols, devices wouldn’t know what to do with the data they receive. It would just be a bunch of 1s and 0s hitting the device’s network card. Protocols define how data is put together into packets for transmission and reception, and then interpretation at the receiving end – what the device should do with the data.
For example, your devices have an Internet Protocol (IP) address. Incoming data uses that address to find your device, but it also uses a port number to identify what your device should do with it. Should it present it in a web browser, or send it to your email program? Protocols help your device, regardless of what kind of device, use the data from each port in the same way each time. It works basically the same way for every email program and every web browser. They may look different and offer different features, but the email messages are going to be the same messages, no matter what email program you use to view them.
What this means for you is that you don’t have to do things differently if you use Outlook or Gmail to read incoming emails or send outgoing emails. The differences aren’t in the messages themselves; the differences will be primarily cosmetic.
The same is true for web browsers. The browsers may look different and offer different features, but you don’t have to do anything different to read this blog post on Firefox than you would have to do on Chrome or Edge. The browsers all know what to do with the data that forms the web page, because web pages all use the HyperText Transfer Protocol (HTTP) or HyperText Transfer Protocol – Secure (HTTPS).
Common Types of Protocols
There are thousands of protocols defined by the Internet Engineering Task Force (IETF), but only a few hundred are in use today. We can narrow it down even further by saying that there are only a few that are useful for most people to care about.
Internet Protocol (IP) is the addressing system. Every device, on joining a network (and the internet is one huge network), needs an IP address from somewhere that is authorized to give those addresses out.
Transmission Control Protocol (TCP) is a delivery protocol that ensures reliable delivery of data. TCP has a counterpart called User Datagram Protocol (UDP). While TCP requires a “connection” to guarantee delivery, UDP is a connectionless protocol, and, as a result, offers no delivery guarantees.
I mentioned HTTP and HTTPS, which are the browser protocols. They’re used by your device to make page requests (clicking a link or typing an address) as well as to deliver the pages back to you.
Email uses several different protocols to accomplish the delivery of messages in different ways. SMTP is the sending protocol, and IMAP and POP3 identify what to do with it on the receiving end.
Bluetooth is a short-range handshake protocol between devices. While you have to pair each device with each device, you don’t typically need to know something different about how to do it for each different device.
There are a bunch of different generations of WiFi protocols, each one improving on some aspect of the previous generation. Again, you don’t need to know anything about them to make use of them; your devices can handle all of that.
Protocols You Don’t See (But Rely on Daily)
There are some protocols that work quietly in the background, and they do their job so well we never even think of them. File transfer is one of the oldest protocols. When you download or upload files, you’re using either File Transfer Protocol (FTP) or Secure File Transfer Protocol (SFTP).
Secure online financial activities are possible due to secure communication protocols like Secure Sockets Layer (SSL), or, more recently, Transport Layer Security (TLS). That’s what puts the little padlock up in the corner of the address bar of your browser.
Real-time Transport Protocol (RTP) is what we use for streaming. It isn’t about moving files around, but moving streams of data. Zoom meetings, Voice Over IP (VOIP) phones, and video transmissions all use this.
One of the most important protocols in networking is the Domain Name System (DNS). It resolves names to IP addresses, so you don’t have to remember the IP address of every site you want to visit. There are servers around the world that do the work of that translation, and without it, the web would be a horrid mess.
Your Turn
So, now we know that protocols are the Miss Manners of digital communication. Learning the basics of these things can help demystify how devices talk to each other.
Now, instead of leaving a tech comment, drop a comment on a protocol or rule of etiquette that you find very useful or satisfying, just for fun.
Here are a couple of sites that dig deeper into it:
What is Protocol? Definition, Types & Use Cases – Techopedia
What Is a Network Protocol, and How Does It Work? | CompTIA Blog
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