Comcast Cable CTO: Bandwidth Hogs Will Experience Slowdowns

43 Comments

Comcast recently announced a deal with BitTorrent that left me dazed and confused. It was basically a roundabout way for the cable company to backtrack from its P2P traffic-blocking gaffe. In describing the deal, Comcast tried to shift the focus away from their so-called “network management” — and by extension, the limitations of their network that prompted them to resort to traffic manipulation in the first place.

On Friday, I caught up with Tony Werner, chief technology officer of Comcast Cable, to get the real skinny. When asked to explain the so-called announcement in language a simpleton like me could understand, Werner said: “Historically we had looked at a basket of P2P protocols during peak load times and would slow them down. In the new approach, we don’t do this any more.” In short, no P2P blocking!

Werner said that between one half and two percent of Comcast’s customers can be described as “bandwidth hogs” — users that consume so much bandwidth that it can cause network quality degradation. According to Werner, the company is currently experimenting with software (including that from Sandvine) that would allow them to fractionally de-prioritize the traffic from these bandwidth hogs during peak load times, while at other times, leaving them alone.

Comcast will not discriminate against any protocol, but bandwidth baddies are going to be the ones to suffer. Or at least that’s what I took away from our conversation.

Problem is who’s to say they’re not going to manage everyone’s traffic? Although a company spokesperson assured us Comcast will be clear and transparent with anything related to traffic management, my skepticism stems for Comcast’s past actions. When it comes to traffic management, the Philadelphia-based operator has a checkered past.

Comcast assured the FCC during the Network Neutrality deliberations in 2005 that it would not degrade traffic; it repeated the assurance again in 2006. Yet the company started “traffic managing” that very same year. And now they’re cleaning up their act?

I asked Werner, why manage traffic to begin with? Why not just add more capacity? “You can’t quadruple the size of the streets and take away all the traffic rules,” Werner said.

He said Comcast is not alone in traffic management, that even in places like Japan, fiber operators that sell 100-megabits-per-second connections are managing traffic, too. “A vast majority of ISPs do perform traffic management, including NTT, and the reason we do it is because we want to have balanced traffic performance at peak times,” Werner said. (See here for “Why Shaping Traffic Isn’t Just A Comcast Issue.“)

Of course, my views on broadband align with those of French broadband maverick Xavier Niel, who believes giving people more bandwidth — not getting in their way. Still, his view (and mine) are the minority in a broadband world dominated by large incumbents.

For their part, the incumbents have started to talk about taking a protocol-agnostic approach to traffic management. They have to, otherwise we’ll have more snafus like the ones experienced by the Canadian Broadcasting Corporation. Although the CBC released a torrent legitimately, downloaders had a hard time grabbing the video shows. Werner’s comments and recent throat-clearing by Verizon and AT&T reveals a thaw in ISP views on P2P. [digg=http://digg.com/tech_news/Comcast_Bandwidth_Hogs_Will_ExperiencenSlowdowns]

On a larger scale, Werner said traffic management is “very tricky.” “We need to get the whole industry together and tackle this issue,” he said.

43 Comments

Sam

I think we’re all forgetting that Comcast charges egregious amounts for internet service and obviously spends next to nothing on customer service. They also outsource tech support so they’re not paying a premium there either. My point is that there’s no real reason why Comcast can’t provide virtually unlimited bandwidth for everyone.

Think of it this way: Comcast moves into an area and spends X on setting up their bandwidth infrastructure. Now, imagine that they’ve covered an entire city. Every time they moved into a new part of town they had to have X amount of money to spend on setting up that infrastructure. After they’ve covered the whole city, they continue to make money that they would normally have spent on moving into new areas except now the whole city is covered. That money can now be used to add bandwidth to the areas they cover.

The money is there. Comcast could be offering unlimited bandwidth if they wanted to but since they have no real competition in most areas where they are, they don’t have to.

netequalizer

I like this analogy (below) on rationing resources. This excerpt is taken from the NetEqualizer blog site. It is relevant to this discussion because many smaller ISPs around the world delegate bandwidth based on behavior without actually looking at a customers data. It sounds like Comcast may be adopting some of their techniques.

The NetEqualizer methodology for application shaping has been agnostic with respect to type of data for quite some time. We have shown through our thousands of customers that you can effectively control and give priority to Internet traffic based on behavior. We did not feel comfortable with our Layer 7 application shaping techniques and hence we ceased to support that methodology almost two years ago. We now manage traffic as a resource much the same way a municipality would/should ration water if there was a shortage.

Customers understand this, for example if you simply tell somebody they must share a resource such as: water, the internet , or butter (as in WWII), and that they may periodically get a reduced amount, they will likely agree that sharing the resource is better than one person getting all of the resource while others suffer.

Well that is exactly what a NetEqualizer does with Internet resources albeit in real time. Internet bandwidth is very spiky, it comes and goes in milliseconds and there is no time for a quorum.

taken from

http://netequalizer.wordpress.com/2008/03/28/comcast-should-adopt-behavior-based-shaping-to-stay-out-of-trouble-opinion/

pbx

As long as they are fair, its fair. No protocol discrimination. When a hog on your pipe takes your bandwidth, you want Comcast on your side. Now if they want to mess with something, how about filtering SPAM! SPAM is probably screwing the net far more than Bittorrent, etc.

JBrown

There are newer technologies, such as P2P caching, that enable ISPs to intelligently manage P2P traffic, in a way that simultaneously provides a superior experience to everyone – P2P users and non-P2P users alike (or hogs and non-hogs, as the case may be).

http://en.wikipedia.org/wiki/P2P_caching

Larry Marks

I am strongly opposed to bandwidth “management” as it has frequently been applied for p2p and other high bandwidth applications. In the case of Comcast, the real reason for their “management” is preemptive – it is intended to prevent traffic congestion before it happens.

Intelligent network management is reactive, not preemptive. it should occur only when congestion actually begins to occur. This is congestion management. On those RARE OCCASIONS when congestion management is required, the managers should do several things:

First of all, the network’s managers should, as you suggest, look at increasing available bandwidth if congestion is occurring regularly or for extended periods of time. There is no shortage of fiber available to Comcast.

Secondly, the managers should look at what protocols can stand delay during congestion with little impact on the users. First target should be e-mail. Users will likely not even notice delays in this traffic. There are other protocols, including Comcast’s own network management traffic, that can be delayed with little impact on users.

But in a correctly managed network, congestion should occur RARELY. If it occurs more frequently, the managers are simply not doing their job. And Comcast’s preemptive management philosophy is simply BAD network management. No professional I know would approve of this approach.

Jim Boult

If Comcast had been forthright with its’ advertising to customers in the first place, the customer would know the limitations and make their buying decision based on the facts and not the fiction portrayed by Bill and Carolyn Slowski and the mercury like substance they call “High-Speed”. When people have taken Comcast at their word and later find out that they have been lied to based on the term unlimited meaning something different to Comcast, this is where Comcast gets themselves in trouble with truth in advertising.
Many of the new products and services that Comcast has rolled out in the past couple of years are the biggest “Bandwidth Hogs” of all. With Comcast not preparing for their increased bandwidth usage in advance to the deployment of these new products and services and trying to place the blame for the bottlenecks on their users which use the most bandwidth that they paid for, I call that criminal.
Comcast is now trying to placate their users by saying that they will only be slowing from ½ to 2% of their customers who they claim to be “Bandwidth Hogs” leading customers to believe that they won’t be affected by their so-called “Network Management”. Two days ago Comcast claimed that only ½% of their customers were “Bandwidth Hogs” … now the numbers have jumped to ½ to 2% of their customers. I trust Comcast about as much as I trust a fox in the henhouse.

VTFootballGrad

It beats the alternative. I had to use a service that wouldn’t let you route their service and kicked you off the internet if you downloaded anything. I’ll take the bad comcast service over that terrible service any day.

JL

@JL Plenty of smart people own and operate my chosen provider of electricity ( TXU here in Texas ) but they have no desire to “control” or “dictate” what I do with the juice – Can you imagine?!?!?! The more electricity I use, the bigger the monthly bill, that’s it. There is no mention of who can ( or cannot )use the electricity for Power company “approved” uses.

Oh — and one other IMPORTANT difference. Your electricity is METERED, no flat rate. So are you suggesting that ISPs should move (back) to metered rates?

JL

@JL Plenty of smart people own and operate my chosen provider of electricity ( TXU here in Texas ) but they have no desire to “control” or “dictate” what I do with the juice – Can you imagine?!?!?! The more electricity I use, the bigger the monthly bill, that’s it. There is no mention of who can ( or cannot )use the electricity for Power company “approved” uses.

So your power provider has never had brownouts, when demand outstrips capacity? Isn’t that similar to network congestion at peak times?

Dave Burstein

Om

Tony is wrong about congestion on the 100 megabit pipes in Japan. Ain’t so, a lie repeated by many. I was on the original D.C. panel where a reporter misunderstood a chart.

Dave Burstein

Alan Wilensky

The downstream leg is not the problem, really. Comcast made a decision very early in the build out to limit the channel capacity back to the headend. So, upload congestion started becoming the norm when torrent clients started the dance. Also, the growth of video uploads in general was never anticipated back in the day.

The current best the Comcast can do is 90-120KBPS up. and, that’s a damn shame in this day and age.

Todd

@JL Plenty of smart people own and operate my chosen provider of electricity ( TXU here in Texas ) but they have no desire to “control” or “dictate” what I do with the juice – Can you imagine?!?!?! The more electricity I use, the bigger the monthly bill, that’s it.

There is no mention of who can ( or cannot )use the electricity for Power company “approved” uses.

JL

Re: ‘P.S. Comcast you and all the other ISPs are just “dumb pipes” the sooner you accept that reality, a better place the world will be.
http://en.wikipedia.org/wiki/Dumb_pipe

Just read that wiki and it appears suited to mobile operators with a walled garden, so perhaps that is more applicable to the vintage AOL walled garden experience?

And the further scenario cited is that of the iPhone, where any device can be connected to the network, which is of course how any broadband service already works today.

But if network operators are to believed, just providing basic bandwidth and speed necessitates some form of ‘smart’ network management. So even if someone runs a dumb network they still need smart people to operate and optimize it, and good software/hardware/infrastructure.

JL

Re ‘just add more capacity’

In one of the press releases or articles they did in fact say they were adding network capacity, which is good. But I encourage anyone to read what the Japanese ISPs are experiencing, and to read the recent ZDNet article on this topic (George Ou wrote it I think). Basically it appears that other countries are seeing their pipes fill to capacity as soon as they are built, and the ZDNet article points out some short-comings in TCP itself on this matter.

Re ‘Problem is who’s to say they’re not going to manage everyone’s traffic? Although a company spokesperson assured us Comcast will be clear and transparent with anything related to traffic management, my skepticism stems for Comcast’s past actions. When it comes to traffic management, the Philadelphia-based operator has a checkered past.’

Makes sense to expect greater transparency. Didn’t the press release say they were sharing this practices with BitTorrent and in some way taking this to the IETF? Transparency is good.

Brad

So if they are being transparent about what they are doing, any chance they can clue us in where the high traffic times? It seems like if they published these times, some of the bandwidth hogs would reduce their consumption at peak times and increase during non-peak times, so as to work with Comcast versus getting comcasted by whatever software (i.e. expensive, customer off putting, etc etc.) they come up with.

James

Rick has a point – obviously, there will always be some bottleneck somewhere which must be managed in some way, even if it’s as simple as letting the router at that point drop packets from the relevant buffer, the default “traffic management” policy which has prevailed across the Internet for as long as it has existed.

If Comcast applies a cap fairly – so that if 20 people all try to pull data across the same 155Mbps (OC-3) link somewhere, they each get a fair share of 7 Mbps or so – it’s reasonable – my objection comes when they start killing off one protocol (like BitTorrent) to leave more room for others like HTTP, and that seems to be precisely what Comcast were doing previously. I don’t mind not being able to max out the 8Mbps capacity of my ADSL line when the network’s busy (although obviously I expect my ISP to invest in maintaining performance as traffic grows) – but when they start artificially restricting the connection’s performance based on how they think I’m using it, I object.

Todd

To poorly paraphrase Star Wars episode three…”This is how Net Neutrality dies, with thunderous applause…”

Rick

I believe Comcast is doing the right thing. Traffic mgt is necessary. You can’t just keep solving the problem by adding capacity. You have to do both. Make the baddies pay more or slow them down.

Randy Bush

what is a “bandwidth baddie?” someone who actually uses what they were offered and paid for? ahem!

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