By Art Reisman, CTO, http://www.netequalizer.com
Art Reisman
As the Internet continues to grow and true speeds become higher, video sites like YouTube are taking advantage of these fatter pipes. However, unlike the peer-to-peer traffic of several years ago (which seems to be abating), YouTube videos don’t face the veil of copyright scrutiny cast upon p2p which caused most users to back off.
In our experience, there are trade offs associated with the advancements in technology that have come with YouTube. From measurements done in our NetEqualizer laboratories, the typical normal quality YouTube video needs about 240kbs sustained over the 10 minute run time for the video. The newer higher definition videos run at a rate at least twice that.
Many of the rural ISPs that we at NetEqualizer support with our bandwidth shaping and control equipment have contention ratios of about 300 users per 10-megabit link. This seems to be the ratio point where these small businesses can turn a profit. Given this contention ratio, if 40 customers simultaneously run YouTube, the link will be exhausted and all 300 customers will be wishing they had their dial-up back. At last check, YouTube traffic accounted for 10 percent of all Internet Traffic. If left completely unregulated, a typical rural ISP could find itself on the brink of saturation from normal YouTube usage already. With tier-1 providers in major metro areas there is usually more bandwidth, but with that comes higher expectations of service and hence some saturation is inevitable.
If you believe there is a conspiracy, or that ISPs are not supposed to profit as they take risk and operate in a market economy, you are entitled to your opinion, but we are dealing with reality. And there will always be tension between users and their providers, much the same as there is with government funds and highway congestion.
The fact is all ISPs have a fixed amount of bandwidth they can deliver and when data flows exceed their current capacity, they are forced to implement some form of passive constraint. Without them many networks would lock up completely. This is no different than a city restricting water usage when reservoirs are low. Water restrictions are well understood by the populace and yet somehow bandwidth allocations and restrictions are perceived as evil. I believe this misconception is simply due to the fact that bandwidth is so dynamic, if there was a giant reservoir of bandwidth pooled up in the mountains where you could see this resource slowly become depleted , the problem could be more easily visualized.
The best compromise offered, and the only comprise that is not intrusive is bandwidth rationing at peak hours when needed. Without rationing, a network will fall into gridlock, in which case not only do the YouTube videos come to halt , but so does e-mail , chat , VOIP and other less intensive applications.
There is some good news, alternative ways to watch YouTube videos.
We noticed during out testing that YouTube videos attempt to play back video as a real-time feed , like watching live TV. When you go directly to YouTube to watch a video, the site and your PC immediately start the video and the quality becomes dependent on having that 240kbs. If your providers speed dips below this level your video will begin to stall, very annoying; however if you are willing to wait a few seconds there are tools out there that will play back YouTube videos for you in non real-time.
They accomplish this by pre-buffering before the video starts playing. We have not reviewed any of these tools so do your research. We suggest you google “YouTube buffering tools” to see what is out there. Not only do these tools smooth out the YouTube playback during peak times or on slower connections , but they also help balance the load on the network during peak times.
Bio Art Reisman is a partner and co-founder of APconnections, a company that provides bandwidth control solutions (NetEqualizer) to ISPs, Universities, Libraries, Mining Camps and any organization where groups of users must share their Internet resources equitably. What follows is an objective educational journey on how consumers and ISPs can live in harmony with the explosion of YouTube video.
NetEqualizer News Blog 
Can your ISP support Video for all?
January 17, 2009 — netequalizerBy Art Reisman, CTO, http://www.netequalizer.com
Art Reisman
As the Internet continues to grow with higher home user speeds available from Tier 1 providers, video sites such as YouTube , Netflix, and others are taking advantage of these fatter pipes. However, unlike the peer-to-peer traffic of several years ago (which seems to be abating), These videos don’t face the veil of copyright scrutiny cast upon p2p which caused most p2p users to back off. They are here to stay, and any ISP currently offering high speed Internet will need to accommodate the subsequent rising demand.
How should a Tier2 or Tier3 provider size their overall trunk to insure smooth video at all times for all users?
From measurements done in our NetEqualizer laboratories, a normal quality video stream requires around 350kbs bandwidth sustained over its life span to insure there are no breaks or interruptions. Newer higher definition videos may run at even higher speeds.
A typical rural wireless WISP will have contention ratios of about 300 users per 10-megabit link. This seems to be the ratio point where a small businesses can turn a profit. Given this contention ratio, if 30 customers simultaneously watch YouTube, the link will be exhausted and all 300 customers will be experience protracted periods of poor service.
Even though it is theoretically possible to support 30 subscribers on a 10 megabit , it would only be possible if the remaining 280 subscribers were idle. In reality the trunk will become saturated with perhaps 10 to 15 active video streams, as obviously the remaining 280 users are not idle. Given this realistic scenario, is it reasonable for an ISP with 10 megabits and 300 subscribers to tout they support video ?
As of late 2007 about 10 percent of Internet traffic was attributed to video. It is safe to safe to assume that number is higher now (Jan 2009). Using the 2007 number, 10 percent of 300 subscribers would yield on average 30 video streams, but that is not a fair number, because the 10 percent of people using video, would only apply to the subscribers who are actively on line, and not all 300. To be fair, we’ll assume 150 of 300 subscribers are online during peak times. The calculation now yields an estimated 15 users doing video at one time, which is right on our upper limit of smooth service for a 10 megabit link, any more and something has to give.
The moral of this story so far is, you should be cautious before promoting unlimited video support with contention ratios of 30 subscribers to 1 megabit. The good news is, most rural providers are not competing in metro areas, hence customers will have to make do with what they have. In areas more intense competition for customers where video support might make a difference, our recommendation is that you will need to have a ratio closer to 20 subscribers to 1 megabit, and you still may have peak outages.
One trick you can use to support Video with limited Internet resources.
We have previously been on record as not being a supporter of Caching to increase Internet speed, well it is time to back track on that. We are now seeing results that Caching can be a big boost in speeding up popular YouTue videos. Caching and video tend to work well together as consumers tend to flock a small subset of the popular videos. The downside is your local caching server will only be able to archive a subset of the content on the master YouTube servers but this should be enough to give the appearance of pretty good video.
In the end there is no substitute for having a big fat pipe with enough room to run video, we’ll just have to wait and see if the market can support this expense.
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