Skype isn't SIP, Skype is a proprietary P2P protocol. Which is one of the reasons it works so well going through firewalls etc. - Skype had to make it work and could change their implementation at will. (Although most of the magic was already in KaZaA/FastTrack, which the Skype P2P network was based on AFAIK)
Okay, a good point - but does Skype offer much more than you can obtain from a SIP account?
My understanding is that there's a benefit to choosing SIP over skype, because the technology is interoperable and non-proprietary.
I suppose, my point is that people don't need to rely on Skype to be able to call people for free. In my opinion, Skype isn't the only - or even best - choice.
Skype is easier to set up than SIP, doesn't require firewall configuration, or server addresses. You install it, create an account, add people to your list, and insert money when you want to call a POTS line.
not sure why you're being downvoted on this, you bring up a very good point.
Facetime on iphone 4 uses open standards including SIP, STUN and ICE. These are mature p2p technologies heavily used and deployed and are the same used in xmpp jingle specifications.
open standard p2p already won this battle which skype will persist to fight.
Okay, fair enough - a proprietary solution isn't forced to compromise or be subject to approval from standards bodies or general consensus.
However, I'd argue that the fact Skype might work well with firewall's isn't _because_ it's proprietary. An open-standard could work just as well; it would take more effort and time to achieve it, but I think it would be worth the extra effort because the benefit would be more universally felt.
In my opinion, this shouldn't be a primary reason for preferring a proprietary solution over an open standard. If it was, Microsoft's early efforts to introduce proprietary tags into HTML markup wouldn't have been so universally deplored.
