If a comment is posted on the internet, and there’s no one around to hear it, does it still make a sound?

It may sound like the start of a bad joke (mostly because it is), but the digital world was thrown into chaos on Tuesday night, after a major global internet outage took down popular news outlets, ecommerce giants and even governmental websites.

So what exactly happened? And how did we get here?

Back up, the internet went down?

Not the internet per se — but at least parts of it.

Shortly before 8pm AEST, people began to suspect there may be something amiss.

Tweet from @nytimes

Websites operated by news outlets including The Age, Sydney Morning Herald, Financial Times, the New York Times, Bloomberg News, CNN and Al Jazeera were sent offline across the globe, while The Guardian said on Twitter that its website and app had been affected by a wider internet outage.

Other high-traffic websites including Reddit, Amazon, Paypal, Twitch and Spotify were listed as having experienced problems, while the UK government and White House sites were temporarily unavailable.

Tweet from @GOVUK

Those trying to access the affected websites were met with messages like, “Error 503 Service Unavailable”, which indicates a server is not ready to handle the request – often because it’s down for maintenance or overloaded.

At first, the cause was unclear. But it didn’t take long for the unexplained internet outage to be linked to US-based cloud computing services provider, Fastly.

Okay, who or what is Fastly?

The San Francisco-based company is one of the world’s most widely-used cloud based content delivery network providers.

Founded in 2011, it operates a contact delivery network (CDN) – a distributed group of servers that work together to provide fast delivery of content.

It moves content closer to end users, in theory helping sites manage traffic spikes and mitigate security threats.

Tweet from @fastly

The company says putting data and applications at the edge of the network results in a better experience for users, enabling pages to load quicker and sites to manage high volumes of page requests better, for example in a breaking news situation.

Fastly says its services mean that a European user going to an American website can get the content from 200 to 500 milliseconds faster.

Who are their clients?

The company, which went public in 2019 and has a market capitalisation of $US5 billion ($6.4 billion), is far smaller than peers like Amazon’s AWS.

But according to their website, they represent a broad array of clients, including (but not limited to):

• The Guardian
• Business Insider
• Deliveroo
• Yelp
• Shopify
• Shazam
• Ticketmaster
• Four Square
• Virgin Money

What have they said about the outage?

At about 8pm AEST on Tuesday, the company announced it was investigating an issue with its contact delivery networks (CDN) – a geographically distributed network of servers and their data centres that help in content distribution.

About an hour later, it said it had identified the problem, and “a fix has been implemented”. However, it cautioned that “customers may experience increased origin load as global services return”.

“We identified a service configuration that triggered disruptions across our POPs (points of presence) globally and have disabled that configuration,” a company spokesperson said.

“Our global network is coming back online.”

According to Ben Wood, chief analyst at CCS Insight, incidents like this “underline the fragility of the internet and its independence on a patchwork of fragmented technology.

“Ironically, this also underlines its inherent strength and how quickly it can recover,” he added.

“The fact that an outage like this can grab headlines around the world shows how rare it is.”

How has the internet responded?

About how you would expect: with memes.

Twitter users quickly jumped on the global outage, creating the #InternetShutdown hashtag.

“Skynet begins to learn at a geometric rate,” wrote UK-based media company Light-up Media, in a tongue-in-cheek reference to the Terminator films.