jdMorgan - 4:06 pm on Jan 24, 2006 (gmt 0)

> The idea of "QOS fees"

That and the passing mention of "broadband video services" in the PCWorld article, and the "Google Says No to QOS Fees" title of the Light Reading article are really the main point of this disccusion, but one which has been ignored by non-technical writers and the public in general.

Some services, such as video-on-demand (VOD) and voice over IP (VOIP), need a minimum guranteed 'quality of service' (QOS) in order to function properly. Insufficient connection quality on video would lead to missing frames and artifacts in the video. Packet loss can defeat the entire basis of video compression using 'delta coding' where only the changes from one frame to the next are transmitted, rather than an entire new bitmap per frame. Packet loss or delay on delta-coded material is a potentially-'fatal' error, and requires even more bandwidth for recovery.

For voice over IP, the problem is not as severe, but insufficient connection 'quality' would lead to clicks, pops, and voice dropouts in the transmission.

The answer to these problems was QOS or Quality Of Service. QOS allows packets to be tagged indicating whether they are time-sensitive and delivery-order-sensitive or not. Video and voice are both sensitive to delivery delay (latency) and order of packet delivery, whereas downloaded data files, typical Web pages, e-mail, and IM packets are not particularly sensitive in this regard; standard packet retransmission and reassembly techniques are entirely sufficient for these services.

For an example of QOS, see Network Connections->Local Area Connection->Local Area Connection Status->Properties->QOS Packet Scheduler on recent Windows PCs. If you've got this service installed, then your local area network's behaviour is modified: Let's say you are playing a video from a file hosted on another computer on your network. Meanwhile, the person who shares your office space is copying files to another computer on the same network. Without QOS, your office mate's file transfer packets compete directly for access to the network. If his machine or NIC is faster and your network is busy, your video may appear choppy, and may stop occasionally and start 'buffering' in an attempt to prefetch enough data to play it seamlessly for you.

However, with QOS enabled on all machines, and supported by the switches and routers, your network 'knows' that your packets are video, and are therfore time- and delivery-order-sensitive; they are therefore given network priority over the packets sent by your co-worker to transfer files.

So the argument now is that the telecoms are saying that if they are to support this new QOS standard, they want to be paid for the additional infrastructure that it demands (essentially adding 'tollbooths' at the entry points to a separate high-speed lane on the highway). However, rather than offering a "QOS" service to customers who actually use these video and VOIP services and who want higher-quality (guaranteed low-latency and packet delivery) connections, they are trying to open up a new revenue channel by charging the suppliers of these services. In part, I suspect they're doing this to cover large roll-out costs while avoiding having to explain to Joe User just what this extra charges is for. It also neatly adds costs for their voice telecommunication competition --the VOIP providers-- making them less competitive. On the other hand, charging the service provider makes sense in one respect: The locations of the QOS gateways are relatively fixed on the service providers' end... Not so much so on the consumer's end.

So, this isn't a simple 'shakedown' manuever on the part of the telecoms; The datacenter costs associated with QOS are real, and someone will have to pay them in order to support the emerging high-speed video and VOIP services. The media have been disingenuous in reporting this as a 'threatened slowdown' of common Web sites; It is really a needed 'speed-up' of services that place large demands on the existing infrastructure -- most visibly, the video and voice services.

I certainly don't have enough information to say what is fair, but maybe injecting a little bit of technical background will make this discussion more productive. Having worked in telecom, my gut feel is that the telecoms can afford the extra costs if they provision their networks in an unhurried and deliberate way -- Profit margins in telecom are 'very, very good' in well-managed companies I just hope to see some in-depth and responsible reporting on this issue before it's decided based on erroneous and over-simplified reportage.

Jim

P.S. Whatever happened to Google's reputed 'dark fiber' purchases? Are we going to see this QOS debate become the catalyst for Google, the QOS Telecommunications Provider? ;)