Internet firm Akamai has decided to expand its anti-DDoS services by buying security stalwart Prolexic Technologies for $370 million in cash (£230 million), the pair have announced.

Akamai already offers anti-DDoS defence in the form of its Kona Site Defender but nabbing Prolexic will allow it to expand this from simply defending websites to a more rounded defence of data centres and enterprise applications sold as a cloud service.

It’s the words ‘cloud’ and ‘service’ that hold the key to understanding Prolexic’s attractiveness.

“Today, business is defined by the availability, security and latency of Internet-facing applications, data and infrastructure," said Prolexic CEO, Scott Hammack.

"Being able to rely on one provider for Internet performance and security greatly simplifies resolution of network availability issues and offers clients clear lines of accountability. We believe that, together, we will be able to deliver an unprecedented level of network visibility and protection."

By buying Prolexic, Akamai acquires the full suite of anti-DDoS protection in a profitable form that dovetails nicely with its current offerings. And profitable it is likely to be; every survey shows that with the dramatic increase in attacks, DDoS defence is becoming almost as mainstream a technology as preimeter firewalling.

Privately held, Prolexic was founded by in 2003 entrepreneur Barrett Lyon, who coincidentally recently announced a sort of Prolexic mark 2 by setting up another anti-DDoS firm,

But why the need for another DDoS mitigation outfit when his first idea Prolexic has cornered part of the market? According to Lyon, while these first-generation firms can defend against DDoS attacks they can’t stop them shutting down business services in the process. What data centres need isn’t simply big pipes to beat DDoS but better service levels, he argued.