Georgia Tech's ShaperProbe Detects ISP Traffic Manipulation 113
An anonymous reader writes with this excerpt from Ars Technica: "Two researchers at Georgia Tech can tell you exactly how American ISPs shape Internet traffic, and which ones do so. Bottom line: of the five largest Internet providers in the country, the three cable companies (Comcast, Time Warner, Cox) employ shaping while the telephone companies (AT&T, Verizon) do not — though that fact is less significant for the user experience than it might first sound."
not all shaping / policing is bad. (Score:5, Informative)
I work for a college, and we shape / police traffic to / from the Internet.
This was a necessity on our 3Mb link of many years ago, but has still been useful on our 1Gb link of today.
This policy has greatly improved the user experience. Interactive protocols have low latency, bulk transfer protocols get sent to the end of the line. Where we do slow down things, it isn't really noticed by most folks. After first implementing this many years ago, we immediately got positive feedback. Now it is just "how things are."
Hell, I shape / police traffic at home to my cable modem. VOIP and interactive ssh are still usable even with huge downloads going on now, and users hammering the public wifi I provide to my neighborhood.
Re:Question (Score:4, Informative)
no, shaping is done per-protocol, and throttling is done per pipe
Re:Question (Score:5, Informative)
Is shaping the same as throttling?
Shaping is when they give you a rate and enforce it. (The faster burst at startup is because you had accumulated some credit by not using your bandwidth in the immediately preceeding time.) There may be separate shaping mechanisms for different protocol families and there may also be shaping on aggregates - like total bandwidth across multiple users of a common DSLAM.
Throttling is when, after they notice that you've used a lot of bandwidth lately, they turn down the rate on the shaper ("traffic manager").
Shaping is mainly about things like keeping protocols from interfering with each other (by giving different classes of them separate allowances) and avoiding congestion and queue-too-full latency (by limiting the traffic sent to a following box to the amount it can handle.)
Throttling is about keeping a user's resource consumption down by slowing him down after he's run fast for a while.
Re: Is shaping the same as throttling? (Score:4, Informative)
Shaping: controlling bandwidth among various protocols (whether DPI or QoS, port number, etc.). This can be enforced by throttling some traffic or by prioritization.
Throttling: capping or reducing the bandwidth available to some identifiable clump of traffic (I use clump because all the other appropriate terms I can think of have some technical definition more strict than what I want to say). It can be done solely in response to congestion, or in the absence of congestion. It can be done on some subset of a subscriber's traffic, or to the entirety of it. Throttling is a slowing or capping of traffic. Most shaping is a subset of throttling. Oversubscription could be considered a form of throttling. Throttling is much more general of a term than shaping.
ADVERTISED FEATURE of Time Warner and Comcast (Score:5, Informative)
This is said (although almost in passing) in the article. But I will repeat it because i know how few of us RTFA. Time Warner advertises its PowerBoost feature (and Comcast has something similar) where you get like double your usual bandwidth limit for "burst" downloads and then you get throttled back to your limit after the burst is complete. This is a FEATURE they advertise, not something bad. It allows you to (for example) get 15mbit when download a web page or small file on your 7mbit plan. Notice its a 7 mbit plan, they are not throttling you below your plan's rated speed. They are giving you faster downloads for a quick burst. There is plenty wrong with Time Warner, but this isn't one of the the problems.
Re:Cue the cable company bashing in 3...2...1.... (Score:2, Informative)
Are you some kind of retard? Deregulation doesn't lead to any sort of fair balance, it leads to excessive and unnecessary price increases across the board as monopoly situations are reached. Check out the New Zealand power market if you don't believe this happens.
Re:ADVERTISED FEATURE of Time Warner and Comcast (Score:2, Informative)
My neighbors add a couple more tiers to PowerBoost. Weekends the cablemodem borders on useless for any low latency or sustained streaming service (for example hulu, netflix). Weeknights interactive games are tolerable with hit & miss reliability for sustained streaming. Weekday mornings flawless service.
Re:Cue the cable company bashing in 3...2...1.... (Score:3, Informative)
HOWEVER, I also think that we should pass laws FORBIDDING a monopoly into the home. At the least, we should change the monopoly to be from the home to the greenbox and any company can then sign up for a deal with providing service to the greenboxes, AT THE SAME RATES. IOW, if comcast wants to own the greenbox-home monopoly, not a problem. However, they charge other providers the same price that they charge the rest of comcast.
That is kind of how it works in the UK (See how British Telecom has been split up [wikipedia.org]).
BT Openreach was created to "Ensure that all rival operators have equality of access to BT's own local network" and it works pretty well, I have a BT line and BT Wholesale broadband, but provided by a different company with their own service levels, prices etc. And there are a lot of ISP's like this.
If an ISP doesn't want to use BT's infrastructure in the exchange, they can even install their own [wikipedia.org] whilst still taking advantage of that piece of cable going from the exchange to the home, laid down by public money.
How is it not obvious to the US politicians that this is a sensible move? More to the point, how the hell did something sensible happen in a UK Parliament?