It is always said that Quality of Service (QoS) mechanisms are important for VoIP, but what does it mean in practice? Well, as long as that Skype connection just works it doesn't really mean a whole lot. It suddenly means a lot though, when the call breaks up and the other end is barely understandable due to congestion that provokes rapid round trip time changes between 300 ms and 1600 ms in the course of just a few seconds.
This happened to me recently and at the time I wished I had some QoS preferring my VoIP packets over whatever else the other 99 participants of the meeting were transferring over that Wi-Fi link connected to a way too slow backhaul link at the time. It suddenly makes you aware of the benefits of network enforced QoS. And it must be the network because otherwise half the participants would immediately tweak their PCs to demand a better QoS for their packets irrespective of the application. Well, that's at least what I would do...
So in the end I resorted to making a call over GSM. Just another way of getting QoS, really, just not on an IP bearer.
And despite tons of buzz on QoS for many years, there is still no universally working way to get QoS for a Skype call on a real network.
Posted by: Alexander D. | July 17, 2010 at 08:51 PM
I think I know why when I make a VoIP call using Skype the call quality is not so good after reading your post.
Posted by: VoIP software | July 26, 2010 at 06:01 PM