Do you ever wonder what factors impact your experience using VoIP technology? Very recently Celideo, a maker of testing tools for voice and video over IP, posted a very nice summary of the issues surrounding VoIP quality. The post is entitled, “VoIP QoS Metrics Explained” and I find it a good tutorial on the subject. It’s comprehensive yet concise, and given in easy-to-understand terms.
Earlier this week I found a newly launched VoIP QoS monitoring service called VoIP Spear. It works by sending a ping to the end-point in question at a certain interval, then analyzing the timing of the resulting responses. The service is free for monitoring a single end-point so I setup an account and pointed it at my office IP address.
However, Manuel Kasper (m0n0wall project lead) had some interesting ideas on how to revise and perhaps simplify my approach. What he describes departs from the approach underlying the present implementation of the Magic Shaper in m0n0wall. Use of the Magic Shaper is the basis of the existing screencast.
Updated to provide a YouTube version in the post and ftp downloadable high quality version.
Brough Turner has written an updated version of his classic opinion/overview of network QoS. His opinion that we’ll never have end-to-end QoS on the internet raised some eyebrows in December 2006…but he was dead right, and remains so to this day.
The updated version includes some new information about potential business opportunities for farsighted ISPs who might offer a better class of service through ensured QoS.
Not to give away the punchline, but here’s his summary:
There is no Internet QoS today, and it’s unlikely any complex QoS scheme will ever be added to the Internet as a whole. To the extent next generation networks with rich QoS are deployed, it will only be within walled gardens. But there may be opportunities for ISPs to create a simple premium service that could generate incremental revenue.
It’s a good read, not too technical and with references from good solid sources.
My own posts about small network QoS and traffic shaping have been the most popular posts since I started writing this blog. There appears to be real hunger for information about this stuff. Brough gives us a definitive overview of the subject.
My series called The Beginners Guide To Sucessful VOIP Over DSL was just republished over at Small Net Builder. Tim Higgins, the editor over there, has been very supportive of my recent efforts. Where they are interested I may be blogging about some of my projects on their site as well as here on my own.
Jared Valentine has posted an interesting description of a system he developed for automatically manipulating QoS & bandwidth allocation to support the use of VOIP over his DSL service. He calls this “Application Aware Triggered QoS.”
He described his initial problem as being trouble with inbound bandwidth management. This is something that I’ve never experienced myself. My trouble was always related to limited outbound bandwidth.