Skype All Hype?


Skype has become the darling of the media and blogosphere, and whatever modicum of skepticism that was there about its claims has vanished into thin air. Most are impressed by 41 million users (though no one can substantiate the number). Except one man – Aswath Rao who unmasks the Skype claims in his latest post. Niklas Zennström, CEO of Skype told EE Times , “Skype is the only one that uses peer-to-peer technology for voice services. Other VoIP services are using a client-server technology… It can take advantage of full broadband bandwidth, so you don’t need to compress the voice as much to get a richer sound experience.” Aswath thinks that the statement is a bit of bull. because Skype’s supernodes are nothing but servers, and clients are on your desktops. He takes the claim of the superior voice quality is a bit misleading. Read the full post.



In your typical SIP network, the SIP – call signaling – often travels client-server. The client sends its signaling to (or receives its signaling from) a network application server of some sort.

But the RTP – the voice – often travels peer-peer. Only the worst NAT scenarios change that — no different than the supernode bouncing that takes place in the Skype world.

When traveling peer-peer between two clients that are capable of dealing with “full broadband voice” SIP clients can sound like Skype clients. Compressed voice comes into play in bandwidth challenged scenarios. The other loss of fidelity comes in the handoff to the PSTN at the TDM media gateways. Of course, this should come as no surprise to the Skype user who buys Skype-Out time and finds out what a PSTN handoff sounds like.

Comments are closed.