How Information Moves Around The Internet

If you want to understand digital security better, it’s worth taking a moment to look at how information moves around the Internet, in particular your information. Just how is data sent from your PC across the Internet, to potentially fall into the hands of someone else?

Information Superhighway

The Internet is a huge, complex network of computers and is widely credited as humanity’s greatest achievement. It’s estimated that the Internet houses something in the region of 10 to the power of 24 bytes of information, which is quite a big number (10 followed by 24 zeros).

That estimated amount of bytes equates to an exabyte of potential information held by every single connected device that makes up the Internet, some of which is your information. It’s an impossible number to visualise, since we’re only using gigabytes or terabytes of storage in most of our devices. More to the point though, how on earth does all that connect together, and how does it work?

To be able to transmit all that information, the data that travels around the Internet is in packets. Each of these packets contains a header and a footer. The information stored in the header and footer contains the details regarding the data being sent. For example, if you send an email to someone, as soon as you click the send button the data will be wrapped up in headers and footers, split into numerous packets and sent on its merry way.

Whilst that sounds logical, much in the same way a telephone call takes place, the reality is quite different. Those packets can take any route possible to get to the destination, as defined by the header and footer. Those routes don’t necessarily all have to be the same either. Some packets may travel from one server to the next via one data pathway, while others will take another. The server at the other end will use the information provided by the headers and footers to collate the message, reform the data and present it to the email recipient the way in which you intended it to.

Remarkably, if the server at the other end detects missing packets it can request the missing information from its available connections. Any missing data can then be sent via an alternative route, updating the information as it goes so other packets will know that the previous route isn’t getting through. The headers and footers then tell the server that the data packets are all present and what they should look like; the email will arrive accordingly.

All this happens in milliseconds. This sounds incredibly complex and on paper it makes the Internet appear to be a slow, lumbering beast dealing with incomplete packets of data. In a way that’s how it works but instead of being a lumbering beast, the Internet or more accurately, the servers and computers attached to it, are fathoming data packets by the millions every second.

digital security

Just as we’ve seen, each computer on the Internet is connected using an IP address. These are registered across the Internet, so the headers and footers in each packet contain the IP address of the sender and where the data is heading to. That way, it’s not just a random collection of data travelling across the ether in the hope of landing in the right place. The DNS, Domain Name System, converts the IP addresses to readable names, such as Google.com and the like, and back again. That way when you enter the email address someone@somewhere.com the DNS servers will convert the information and the packets sent to the relevant destination.

The protocols used throughout the Internet define what the data being communicated actually is. For example IMAP, Internet Message Access Protocol, is a mail protocol for accessing email on a remote server, such as accessing Gmail. These protocols help further the transmission of data to its intended location, making it more accurate and telling the computer on the other end what it is and how to piece together the jigsaw puzzle of packets that will be received.

Essentially this is how information is sent and received around the Internet. Obviously, there’s a lot more going on in the background than we’ve mentioned here. The complexity that you can go into when dealing with data transfers is quite staggering and a little bewildering at times. Suffice to say, all those packets of data contain information about something or someone and somewhere out there are packets of data that contain information about you, where you are, what you’re doing, and other personal details such as bank accounts, passwords, names and addresses.

David Hayward

David has spent most of his life tinkering with technology, from the ZX Spectrum, getting his hands on a Fujitsu VPP5000/100 supercomputer, and coding on an overheating Raspberry Pi. He's written for the likes of Micro Mart, Den of Geek, and countless retro sites and publications, covering reviews, creating code and bench testing the latest tech. He also has a huge collection of cables.

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