How data reaches our computers

Our reliance on internet data means it’s easy to take connectivity for granted.

Everything that happens on our computers, smartphones, TVs and consoles can be broken down into a string of zeroes and ones – the binary data powering any digital device.

Every website you visit, every program you watch and every email you send involves a vast array of zeroes and ones being beamed around the world in fractions of a second.

Each zero or one is referred to as a bit, and groups of eight bits are commonly bundled together into a byte.

Internet data is transferred in packets containing no more than 1,500 bytes – a miniscule fraction of most media files, webpages and other online content.

It’s worth bearing this in mind next time your broadband router has a momentary outage, since it’s quite miraculous the internet works at all…

From server to screen

In the main, we tend to consume online content rather than produce it.

Third-party content is uploaded to gigantic warehouses, where it’s stored on specialist hard disc drives known as servers.

These servers are designed to distribute information to multiple destinations at once, using large amounts of internet bandwidth and processing power to multitask.

When you’re online, your devices are constantly sending requests to host servers for information such as webpage content or music files.

This information is converted into binary data packets, and distributed down a global web of internet connections.

Long-distance fibre cables transmit internet data at the speed of light, though the connections between local telephone exchanges and our homes are often relatively sluggish copper wires.

Data packets regularly arrive out of sequence, depending which routes they’ve taken from server to screen.

(Some routing protocols choose the shortest route between server and screen, while others seek paths with the shortest delay – known as latency).

The recipient device then has to reassemble received packets into their original format – a portion of video footage, character movements in an online game, a breakfast selfie, etc.

Each packet is wrapped around header and footer data explaining where it came from and where it’s going, as well as which part of the overall file it comprises and what data it carries.

Once it’s been reassembled in the correct order, the information is displayed on your device.

Incredibly, this whole process typically occurs in less than one second. Until something goes wrong, that is.

How (and why) things go wrong

There are numerous factors which might interrupt the steady stream of internet data:

• A dropped connection. Broadband routers and microfilters occasionally stop working, while software glitches and malicious activity can also cause a connection to fail
• Broadband provider outages. Less commonly, your broadband provider could experience a major failure, like last December’s mass outage across the O2 mobile network
• Network traffic. It’s harder for data packets to reach their destination when the internet is busier. A packet might set off along one route, but then have to follow a different path
• Nodes. Every time data packets are distributed through a server, router or another node on the internet, delays increase and there’s a risk of data packets being lost or delayed
• Overloaded servers. If too many data requests are received by a server, it may stop working. This could happen deliberately, as part of an orchestrated DDoS attack
• Malware. Similarly, malicious software squatting on a device’s hard drive might redirect internet bandwidth for other uses, or throttle internet speeds out of sheer devilment
• WiFi interference. Issues within the home may also affect broadband delivery, such as wireless interference from baby monitors or too many devices hogging bandwidth
• Client device limitations. Running too many programs or filling internal storage can diminish a device’s ability to request and process received data quickly enough.

Next time a website takes a few seconds to respond, or you experience a slight stutter in video streaming, remember what’s actually involved in digital data transfers.

It helps to put minor inconveniences like router reboots into perspective.