What is QoS? It is not a Latin word or a word in some other language. Its origin had nothing to do with politics. But it is important in understanding the battle over net neutrality.
QoS stands for quality of service. The service in question is network data being delivered in a timely manner.
To explain how this works I will to briefly try to explain how Internet data moves. I am sure many Kossacks already know this, some know it better than I do. But I want everyone to understand why the technical problem dealt with in QoS could be used as an excuse to wreck net neutrality.
The Internet uses packet switching to deliver data. The data is divided into packets, and each packet is sent out into the network. As each packet is received by the next stage of the network, the packet header containing the destination is used to decide where to send it next. There is a large infrastructure to enable all of this packet routing to work, with IP addresses, DNS, many levels of routers, etc.
These packets are routed independently of each other. Most data is what is called "best effort", which means it gets there when it gets there. If there is too much traffic, there can be delays long enough to be annoying.
But now, there is more and more traffic where "best effort" might not work. Text or still pictures don't care about the arrival times of packets as long as all of the data gets there. But video or audio has to arrive fast enough to keep the time of the picture or sound intact. If audio of 20 seconds takes 30 seconds to play, it won't sound right, or might be incomprehensible. Video has the same problem.
Internet video tries to compensate for this problem by prereading video data before it starts displaying it, so if a glitch occurs and some video data arrives too slow,, it has a chance to catch up while still displaying the data it has already read. When you see a YouTube video, you can see on the bottom of the window a bar with a dot on it. The bar shows how much video data has been read, while the dot shows where the video is currently displaying. If the network is doing ok, the data read bar should stay ahead of the dot until the very end.
But some video or audio can't take advantage of pre-reading. If you are doing a phone call on the Internet (VoIP, voice over Internet Protocol), you don't want to wait for pre-reading before you hear what your caller is saying. For voice it usually works since the bandwidth requirements are relatively low, but there still might be gaps or broken up sound if the network is congested. Live streaming video is much more difficult since video requires much greater bandwidth. Video phone calls, such as the FaceTime feature on the iPhone 4, require predictable data transit times to get a good picture. Any live video, such as Webcams, can run into this problem.
Quality of service is the network technology name for methods to create a predictable and guaranteed network delays and bandwidth for data such as live video that needs to delivered within a time constraint. With QoS, live video or audio can be received with a predictable quality.
But QoS methods rely on reserving network bandwidth for some traffic so the transmission is predictable. It is like having a special bus lane in a highway system, so that buses can keep their schedule even if there are traffic jams. If too many lanes are reserved, the rest of the traffic gets congested a lot faster.
Here is where we get to net neutrality. The companies that control the network want to reserve network resources for QoS, so that they can charge extra for traffic that uses it. If they can make more money selling QoS resources, the rest of the network is in danger of being congested.
But this is not the biggest problem. They are using the QoS services to get their foot in the door of controlling content. If they are going to have privileged content, then the content that gets privileged will be whatever content meets their corporate goals. The control of content will pass to the network. Imagine if Ford bought the Interstate Highway system, and announced that any car that was not a Ford would have to pay a high toll to use the highways. The Comcast NBC merger invites a similar situation with the Internet. Does anyone think that Comcast might be tempted to give NBC priority on their network, and maybe charge anyone else providing content a high price to get on the net?
Content is the key question. To keep the Internet we have now, where anyone has the opportunity go for a global voice, we must keep content and delivery separate. The Internet should be regulated as a common carrier, like the phone system. The Internet will be regulated, the only question is whether it will be regulated by corporations or by the government. If corporations regulate it, they will regulate it in their own interests, not the public's.
We can't allow QoS to be the wedge used by net corporations to gain control over content. The engineering problems of video can be dealt with without giving away the Internet.