What Is an Internet Protocol? The Plain English Explanation

What is an Internet Protocol? The plain English explanation is fairly simple. At a glance, an Internet Protocol (IP) is a set of rules that stipulates how data is sent and received through the Internet.

At its heart, an IP is similar to a spoken language. The computer receiving data needs to be speaking the same language, with the same kind of language rules, as the computer sending the data.

So, for example, let’s say that Computer A sends data to Computer B in English. However, Computer A speaks American English, and Computer B is configured to listen to Spanish. Therefore, the two computers won’t be able to communicate because they’re talking, and listening to, different languages.

How Does an Internet Protocol Work?

The data sent from Computer A to Computer B is broken down into small data pieces called “packets.” Then, the Internet Protocol defines how these packets are organized based on the network protocol.

Example

Let’s say that Computer A wants to send a bunch of cars (data packets) to Computer B. And it’s a long distance between the two computers.

Traveling on the Network-Leaving Computer A

• Between the two computers, there’s a highway (network) with multiple lanes of automobile traffic (data packets) traveling in each direction.
• Different traffic lanes allow different kinds of automobiles (data packets) and driving speeds (MB per second).
• When an automobile (data packet) leaves Computer A, a postcard (data packet information) is stuck in the glove compartment.
  • The postcard contains the mailing address (IP address) for Computer A.
  • And the postcard contains the mailing address (IP address) for Computer B.
  • Next, the postcard stipulates the size of the automobile (packet).
  • Then, the postcard stipulates the kind of language (transport protocol) it speaks.
  • And, finally, the postcard stipulates how many times (time to live) the car should attempt parking.

Traveling on the Network-Reaching Computer B

• Park automobiles (data) in a garage after reaching their destination.
• Computer B will only accept cars (packets) traveling 5 miles (MB/ second) per hour in the slow lane. (Flow Control via TCP. How about if we chat more on this topic later?)
• If Computer A sends cars (data packets) traveling at 50 miles (MB/ second) per hour to Computer B in the slow lane, the cars can’t be parked quickly enough by Computer B. For example, it’s too many cars (data packets) trying to park in the garage too fast. So, some of the vehicles (data packets) will “do a loop” on the “highway” before returning and attempting to park. Discard (remove or dispose of) the automobile (data packet) if the TTL count reaches zero.
• If Computer A talks to Computer B and asks, “Hey, how fast can I send cars on the highway?” Computer B will say to send them on the “slow” lane. Computer B can accept cars (data packets) at 5 miles per hour.
• Fun fact: Say that you’re emailing a digital picture of your Dear Aunt Sally to your mother.
  • First, the picture of our Aunt breaks down into fifty smaller packets before being sent.
  • Next, those individual packets can take different routes (from San Francisco to Tulsa, while other packets may travel from San Francisco to Seattle, to Austin, to Tulsa) from your email account to your mom’s email account.
  • And finally, packet reassembly happens on the other end, so your Mom sees Aunt Sally! And, hopefully, she smiles.

Different types of Internet Protocols govern how automobiles (data packets) are sent (which lane of traffic on the highway) and received (how the car is parked).

Internet Protocol Addresses

If you want to send your dear Aunt Sally a paper postcard you colored, you’ll need her snail mail address. However, if you want to read something on the Internet (like you’re reading right now), you’ll need the IP address. Everything connected to the Internet has an IP address. And there are two types of them.

IPv4

Internet Protocol Version 4. Dots separate four groups of numbers. For Example, here is the IP address for two popular news websites: 157.166.226.25 (CNN) and 74.120.99.138 (Fox).

IPv4 is 32-bit and can handle approximately 4.3 billion discrete IP addresses. We need more than that to meet humanity’s increasing IP address needs (Aunt Sally’s trusty address notebook is almost full). So, you’ll see a slow introduction to IPv6 (a much bigger address book.)

IPv6

A 128-bit IP address is a key takeaway from IPv6. While IPv4 can handle 4.3 billion discrete devices, IPv6 can handle trillions of devices. That’s a mighty big address book! Google data indicates that roughly 40% of visitors to its site use IPv6.

Different Types of Internet Protocol Addresses

There are four different categories of Internet Protocol Addresses. So, let’s look at each class.

Public Internet Protocol Address

A Public IP is a global address that’s used to access the Internet. Let’s assume you have an Internet Service Provider (ISP) in your residence, like Comcast, AT&T, or Cox.

So, the router you use to connect to the ISP connection has a Public IP address. Furthermore, the devices connected to that router, like your phone, TV, or laptop, have a Private IP address.

Public IP Addresses are split into two categories:

1. Dynamic IP Addresses: When you connect your cell phone (or another device) to the Internet, the ISP will assign you an IP address. When you drop the connection (a quick run to do a little shopping), but return to the exact location later, the ISP will assign you a different IP address. The IP address will change each time you connect to the ISP.
2. Static IP Addresses: It’s a rock! The IP address does not change. It’s the same, yesterday, today and… you know. DNS servers commonly use static IP addresses.

Private Internet Protocol Address

A Private IP is the internal IP address of a device that’s not connected to the Internet. Basically, suppose that you connect your brand-new printer to your home wireless home network. The printer has a connection to the wireless network, but it doesn’t have access to the Internet. So, your neighbors can’t print five full-color, 8.5 X 11 photos on your printer. Whew, one less thing to worry about!

Shared Internet Protocol Address

A Shared IP is a public WiFi watering hole. So, think in terms of visiting Starbucks. You’ll chill, drinking a cold brew and surfing the web on Starbucks’ Wi-Fi.

The Wi-Fi has a Shared IP Address. But, if you were to dive deep, you’d find that everyone connected to that Wi-Fi uses the same IP address.

Be aware: do you remember how your device lets you know, before connecting to it, that your data may not be private? Well, take heed.

Furthermore, have you considered the potential danger of connecting to a network that’s not so private? The danger is real, so you might think twice before connecting to a shared IP address.

Dedicated Internet Protocol Address

Your domain has an IP address that other domains don’t use or share. So, it’s your, and only your, home on the Internet.

Transport Protocols (TCP)

The Transport Protocol defines data transfer between computers.

• Tracking packets sent or received.
• Each packet has a number assigned to it.
• Then, each packet has a size assigned to it. How big is it?
• Keeps track of the data order. What started as packet 1 needs to finish as packet 1.
• Flow Control (We told you we’d come back to this!) restricts the data flow rate. Computer B’s “Flow Control” tells Computer A to slow down if the data can only come in at 5MB per second.
• Checks for corruption errors and lost data packets.
• Is the highway crowded in middle-America? Finally, after determining the congestion levels, some data packets go from Computer A to Computer B via a different route.