Skype announced today that it's almost done moving to a modern infrastructure.
For what it's worth, the move has been in the works for quite some time now. However, it wasn't until today that Skype revealed that the transition toward a cloud-based system and away from a peer-to-peer (P2P) one, is nearly complete. Once it is complete, the company will maintain support for Android 4.03, Windows 10/9/7/XP/Vista and iOS 8, but leave Windows Phone 8 and older versions of Android behind.
So, what prompted this move? Simply put, there are too many issues with a P2P system when compared with a cloud-based one to make it worth using anymore.
When Skype was first introduced in 2003, its network was built as decentralized P2P system. PCs that met the right criteria (processing power, bandwidth, etc.), were elected as "supernodes" and used to coordinate connections between other machines on the network. In a similar vein, text, voice and video traffic would flow between peers either directly when possible or indirectly through other systems on the network when required.
However, there were three problems with this: privacy, what a lack of supernodes can do to the system and the rise of mobile computing/smartphones.
Up until 2016, the Skype client had leaked IP address information — a violation of a users' privacy. This practice allowed other users on the network to determine which IP address was being used on which account and launched a denial of service attack on a victim. Gamers were particularly at risk, and it wasn't uncommon for disgruntled users who found themselves losing in a game of DoTA 2 to launch such an attack in order to forcibly kick a member of the other team out of the game and tilt things in their favor.
Meanwhile, another flaw with Skype as it was, was that, when a large number of peers go offline, the system goes down with them — as evidenced in 2011 when a software bug caused clients to crash en-masse, resulting in there being too few active nodes to create a fully-connected network.
Lastly, and most importantly, the Skype network wasn't designed with mobile computing and smartphones in mind. It was assumed that the world always uses permanently-connected desktop PCs, with bandwidth and processor power required to act as supernodes. However, mobile computers and smartphones introduced a surge of users who were only intermittently connected and failed to meet the requirements needed for Skype to act as a complete, fully-connected network.
To combat these problems, Microsoft added dedicated supernodes in 2012 (though still relying on a P2P system), and has since developed a more conventional client-server network, with clients that act purely as clients and dedicated cloud servers.
Now, the company is poised to transition to this system exclusively, and with that transition comes an improvement of Skype's existing features.
"By moving to the cloud we have been able to significantly improve existing features like file sharing and video messaging, and launch new features like mobile group video calling, Skype Translator and Skype Bots to name just a few," said Microsoft's Skype chief Gurdeep Pall in the blog post.
As stated before, the transition isn't quite done. However, Pall notes that everything should be ready in the "coming months."