WorldOfVoIP

Skype is one of the most popular Voice Over IP (VoIP) software around. It has kind of revolutionized the VoIP field. The reason behind that were the great features it started with:

• excellent voice quality
• free computer to computer voice chat
• support for voice conferencing
• transparent working across NAT boxes
• a peer-to-peer design that allowed it to scale

Skype was developed by the same people who designed the Kazaa file downloading system. They have used the P2P skills they have developed for Kazaa in a very successful way to deliver scalable VoIP. The success of the Skype system can be measured by the fact that Ebay paid around $2.6 billion to buy the company. As per november 2006, skype seems to have registered users of 136 million and expected revenues around $200 million.

Technical Papers

• An Experimental Study of the Skype Peer-to-Peer VoIP System , by Saikat Guha (Cornell), Neil Daswani, Ravi Jain (Google). IPTPS 2006
• An Analysis of the Skype Peer-to-Peer Internet Telephony Protocol by Salman A. Baset and Henning Schulzrinne (about Skype version 1.4)