The Skype Controversy Continues


Greg Scher gripes about Skype, which is fine, but makes some seriously incorrect assumptions. These were brought to my attention by a reader who pointed out these three key points:

  • The article says that after authentication, Skype does not need central infrastructure. This is true only legalistically. Realistically supernodes are part of Skype infrastructure and they could affect the call setup delay while locating the fard-end.
  • Secondly it says that because of encryption privacy is protected. This is true only for exchange of voice. I consider my calling patterns – whom I call, who call me – are private information, but by necessity my Supernode knows this information. It is not clear how Skype ensures privacy of this data.
  • Thirdly, it says that unlike other VoIP architectures, Skype does not have “SIP gateway” etc and so they are abusing VoIP moniker. The comment about the architecture is flat out wrong and I don’t agree that Skype is not VoIP.

Meanwhile Keith points out that nearly 6000 new downloads an hour for Skype. (See the total downloads at the top of the page. That really doesn’t mean anything, because I would like to know how many actual users. People who use it actively!

Andy Writes: According to Kelly Larabee, Skype’s publicist, she told me on Thursday that out of the 20 some million downloads, that 10 million individuals have downloaded the software. the number that Keith and their site refer to are actual clients logged on. Now, that does not mean users, as for example I have three machines on in the house and each is possibly running skype at the same time….or not….depending if I log off and exit or not.



I reread the original article by Greg. I am still missing the difference between “true” VoIP providers like Vonage and Skype. It can not be that Skype is not using SIP (as Rob suggests), for AT&T does not currently use SIP; probably Cablevision and TW use PacketCable from CableLabs. Probably the point was simply that Skype is a proprietary protocol. I would appreciate if Greg or somebody shed light on this.

Rob Evans

if skype uses the internet, then by definition it’s voice over IP (Internet Protocol)..end of story.

The argument is; should voip should be a tag for all voice over internet protocol mechanisms?

Some people, (Greg Scher maybe?) believe that VOIP is a standard using SIP to set up point to point calls using a network. Whereas skype uses a p2p style connection and therefore isn’t truly following the voip standard to the letter.

Greg Scher

Om…I very much appreciate your comments and enjoy the discussion. My piece created much more dissension than I ever thought it would…not that this is a bad thing. The debate is strong…this can never be did.

One point though, I did not infer that the only reason I thought that Skype was abusing the VOIP moniker was because they do not have “SIP gateway”. In fact, those points were made in the reverse order than that which your reader communicated them or you listed them. A small but important point I believe.

There are a number of reasons why I disagree with the characterization of Skype as VOIP. But, as I point out in my piece, Skype is in the technical sense of the term voice traveling over TCP/IP. However, the lack of the SIP client /server infra is not the only reason why I wouldn’t characterize it as VOIP in the biz sense of the term.

In general I am pointing out a nuance here and trying to highlight the differences between true VOIP carriers such as Vonage, and Skype, which I am sure you recognize.

BTW, you make an excellent point in the distinction between the encryption of the call and of the call setup / patterns. I’d be very interested to hear how Skype responds to this.



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