Comcast Defends Role As Internet Traffic Cop

RCTrucker7 writes "Comcast said yesterday that it purposely slows down some traffic on its network, including some music and movie downloads, an admission that sparked more controversy in the debate over how much control network operators should have over the Internet. In a filing with the Federal Communications Commission, Comcast said such measures — which can slow the transfer of music or video between subscribers sharing files, for example — are necessary to ensure better flow of traffic over its network. In defending its actions, Comcast stepped into one of the technology industry's most divisive battles. Comcast argues that it should be able to direct traffic so networks don't get clogged; consumer groups and some Internet companies argue that the networks should not be permitted to block or slow users' access to the Web."

Comments

WSJ doesn't get it.

[robkill]

It's distortions, statements, and mindsets like this that have to be refuted.

From the editorial:

Big broadband companies are headed for a clash with Washington over whether consumers have a right to get as much as they want from the Internet, as fast as they want it, without paying extra for the privilege. The editorial goes on to conflate neutral treatment of packets with "neutral pricing" (their term for flat rate).

Not traffic shaping

[Akaihiryuu]

For the trillionth time...what Comcast SAYS they are doing is NOT what they are doing. Traffic shaping is fine, as long as it does not differentiate by source. Even if they were just throttling or "slowing down" bittorrent, it wouldn't be nearly as bad as what they are doing. They are doing man-in-the-middle attacks on bittorrent connections, and actively impersonating one of the parties in the connection. This is actually illegal.

Sane traffic shaping for cable

[Animats]

Yes, they have to do some traffic shaping, but it can be done better.

If the problem is bandwidth hogging by individual residential users, the answer is probably some variation on fair queuing. There's class-based fair queueing in most Cisco edge routers; it just has to be used correctly.

I'd argue that, for residential connections, you need only two basic classes of service - high bandwidth, high latency, and low-bandwidth, low latency. VoIP and real-time game transactions should be low-bandwidth, low-latency; everything else should be high-bandwidth, high latency.

For the low-bandwidth, low-latency streams, the per-IP-address queue should have priority, but the maximum number of buffers on the queue should be deliberately limited. If you try to send too much too fast with low latency, you lose packets. The high-bandwidth, high-latency streams have lower priority but can buffer up to available router memory. That works for streaming video, music piracy, and similar non-time-critical loads.

Note that putting a high precedence on a high-bandwidth stream increases the packet loss rate, so there's no win in doing that. VoIP should request high precedence, but video should not. Clever game developers should put a high precedence on the traffic that needs it, while letting the background traffic that loads assets run at a lower precedence.

High-bandwidth, low-latency is really needed only for real-time interactive video, and that's a premium service, because it really does need more capacity behind it.

Multiple consumers on the same cable segment contend for upstream bandwidth at the router that connects the cable segment to the larger network. That's where fair queuing has to be applied. Similarly, it has to be applied at the router that connects the backbone to the downlink to the cable segment. Fair queuing is only useful at choke points where the number of streams is limited, but the cable modem industry has exactly that situation.

The cable industry problem, I suspect, is that many of the routers out on the pole are still too dumb to do this. This is a killer for P2P traffic, which saturates upstream bandwidth. Upstream bandwidth has to be properly queued at the router on the pole; it can't be managed from the head end of the cable system. The Comcast "fake RST" interference with connections was an attempt to deal with the problem from the head end, which is the wrong answer.

If the players in cable and DSL would agree on policy in this area, or the FCC mandated a standard, cable performance would degrade gracefully under heavy load. Without idiocy like faking connection resets.

A standard on residential IP precedence handling would be a big help. If application developers could rely on the rules, VoIP traffic would work better. Games could get better latency; only some game traffic, the actual user action traffic, needs high precedence. The background loading of game assets should be running at lower priority. When there's a penalty for requesting too much bandwidth at high precedence, it gets used properly.

From a technical perspective, that's how to do "network neutrality".

Re:If comcast want'sto do this

[ACMENEWSLLC]

What I don't understand is why everyone is so big on rate limiting, versus priority queuing?

If Comcast has 100Mb/s of bandwidth for 500 subscribers (just making up numbers) Their 100Mb/s pipe is not 100% full 100% of the time. Prioritize my P2P traffic to be low priority. That way, if Joe Blow is trying to pull up his sports scores on ESPN, and the pipe is full, then my P2P is put on low priority to burst his ESPN page through. If it's 3AM and it's just a bunch of P2P freaks downloading over an otherwise unused pipe, let us have it.

TCP/IP has an issue with slow start. If the pipe truly is 100% utilized, it will take some time for the QoS to down shift my P2P to allow the ESPN page through. So I can understand a hard limit that 100% of all P2P/Movies/Downloads shall take no more than 75% of the available bandwidth.

Anyway, I run a company Firewall & that is what we do. Works very well as long as you have the proper ratio of bandwidth to users.

Re:If comcast want'sto do this

[Pharmboy]

I'd agrue that it's NOT a whole different ballgame. Both are consumers paying for access.

And you would be showing that you don't know anything about internet access. Business class access comes with a guarantee of throughput, a guarantee of uptime (typically 4 nines, or 99.99% uptime) and a different level of service. Otherwise, we wouldn't be paying $850 a month for 3mbit/3mbit service (two bonded T1s), when 6mbit service is only $50 for homes.

Residential service doesn't cover fully saturating the available bandwidth because it is shared: I can saturate my T1s all I want. Residential doesn't require 2 or 3 year service contracts, but business class often does. Residential service doesn't guarantee to get your internet access back up in 60 minutes or less, even if they have to come string new copper or fiber, but they do on mine. Residential Terms of Service are NOT the same as business class in any shape, form or fashion. The fact that there may be limits on a lower grade of service (residential) shouldn't come as a surprise considering how cheap it is compared to business class.

Yes, that sucks, that is the breaks. If you don't like the limits, you can always go get business class service in your home. Then you don't have to worry about any limitations.

Re:If comcast wants to do this

[budgenator]

I would not have a problem with real traffic shaping, but that's not what they are doing. If they were really just shaping traffic then there would be "prime-times" when the traffic is adjusted down so www and pop travel easier, then at might things would open up so the cron and scheduled tasks could download updates and running BitTorrent full-bore would be over-looked. Instead if you open a BitTorrent client your throttled, period, the whole IP is throttled. If you run encrypted BitTorrent they send resets to any connection open too long, that means if your playing an online game your going to get random freezes and your IM program is going to get kicked off because they are sending out RST packets shotgun style.