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Ask Slashdot: How Can I Prove My ISP Slows Certain Traffic?

Posted by EditorDavid on from the throttling-throughput dept.

Long-time Slashdot reader GerryGilmore is "a basically pretty knowledgeable Linux guy totally comfortable with the command line." But unfortunately, he lives in north Georgia, "where we have a monopoly ISP provider...whose service overall could charitably be described as iffy." Sometimes, I have noticed that certain services like Netflix and/or HBONow will be ridiculously slow, but -- when I run an internet speed test from my Linux laptop -- the basic throughput is what it's supposed to be for my DSL service. That is, about 3Mbps due to my distance from the nearest CO. Other basic web browsing seems to be fine... I don't know enough about network tracing to be able to identify where/why such severe slowdowns in certain circumstances are occurring.
Slashdot reader darkharlequin has also noticed a speed decrease on Comcast "that magickally resolves when I run internet speed tests." But if the original submitter's ultimate goal is delivering evidence to his local legislators so they can pressure on his ISP -- what evidence is there? Leave your best answers in the comments. How can he prove his ISP is slowing certain traffic?

15 of 203 comments (clear)

  1. probably not slowing it specificly by locopuyo · · Score: 4, Interesting

    They might not be slowing down specific traffic but instead just have a poor connection to those popular services and it gets saturated.

    --
    The Official Site of 1337 Pwnage
  2. You can't really by Njovich · · Score: 3, Informative

    Traffic slowed by your ISP, and traffic slowed further down the chain - for instance by poor peering - are indistinguishable. With some help from hops further along like Netflix (or within the ISP) you may be able to pinpoint the exact problem. However, given that so many providers are capable of routing Netflix at acceptable speeds it also doesn't matter, it's obviously your ISP's responsibility.

  3. Alternatively: by Anonymous Coward · · Score: 5, Informative

    Find a free vpn service, like vpngate, and run your connection over to a site (other than netflix, due to geoblocking) that normally runs slow for you. If your speed sees an increase, then yes they are throttling traffic to certain websites. If your speed is the same or less then no your connection to the outside world is just shitty. That is the #1 benefit to vpns for the consumer imho. Unless it is a specific service they are degrading they can't tell who your vpn connects to, and either they throttle all vpns, which commercial users would frown upon, or they throttle none of them beyond regular bandwidth limits and you can find out if that is where the problem lies.

    1. Re: Alternatively: by saloomy · · Score: 4, Informative

      Not necessarily. The internet is comprised of a bunch of networks. If you are getting slow service to Netflix, it may be that you are traversing a saturated peer (maybe your ISP's peer, maybe their upstream provider's peer).

      When you use a VPN, you are routing to a different site, which might have no saturated peers in the chain. Then from that site, you have a decent link to a Netflix node.

      You are routing around using the VPN.

      Also, 3mbps isn't great for streaming. When you say it's slow to Netflix but fast for sites, consider the volume of traffic. Netflix needs 5mbps for HD content, so you probably do t have a slow connection to one site, just in general.

    2. Re:Alternatively: by ColaMan · · Score: 3, Insightful

      It's not "buffering" or a "slowdown", it's advertised as "evening speeds".

      As if it's a perfectly natural thing to experience congestion during the evening.

      --

      You are in a twisty maze of processor lines, all alike.
      There is a lot of hype here.
    3. Re: Alternatively: by silas_moeckel · · Score: 4, Interesting

      If your ISP has a constantly saturated peer that is in effect throttling. We have seen ISP's use BGP traffic engineering to try and push all netflix traffic through a specific peer and then let it saturate the links as a bargaining tool. This should not be allowed. Realy any link that's saturated anywhere inside an ISP or with peers and transit providers should not be allowed in the long term.

      --
      No sir I dont like it.
    4. Re:Alternatively: by Anonymous Coward · · Score: 3, Interesting

      I'm paying $50/m for a 150/150 dedicated fiber with dedicated bandwidth in the USA, at my home. I get 150/150 to nearly every datacenter in the world at every time of the day. They literally advertise ~"We're not like that other ISP. We sell *dedicated bandwidth. You will never experience any slow downs...*Dedicated through out network and to our transit provider".

      When I first got services from them, I talked to the manager of network operations, asked them how they could afford dedicated bandwidth. He said the cost of bandwidth isn't a concern. He said bandwidth is so cheap, they're not even going to get a Netflix CDN, even though it makes up most of their peak bandwidth. Managing bandwidth is more expensive than just buying it. It's plain cheaper just to give dedicated bandwidth than to ration bandwidth. I asked him about the company's position on CDNs in general. He said they had no plans to add CDNs to the network because it's not worth the money saved, but if they did, it would be to make services better, because CDNs can provide lower latency even if bandwidth is not an issue.

      To give a better idea of the cost of bandwidth, talking to their network admin, he said they have 6 transit links, each one is provisioned so much bandwidth, that if 5 of the 6 links went down, their 95th percentile would be around 50% during peak hours. I asked him about DDOS attacks. He said that most DDOS attacks just get soaked by their nearly 10x more bandwidth provisioned than needed, but even in the cases where attacks are larger, they just buy more bandwidth for the duration of the attack. Only takes about 15 minutes to get their bandwidth increased.

      I can stream 149.9Mb/s of UDP over my 150 connection with zero packets dropped over a several hour window that spans peak hours. At 150, I start to see some loss and at 150.1 I see an overall statistical number that nearly perfectly matches being 0.1 greater than 150. One month I decided to ping a datacenter in Europe, ~140ms away. 10 samples per second, for 30 days strait, 25,920,000 total packets, fewer than 100 packets dropped, min ping was 0.1ms less than the average, and the std dev was less than 1ms with a max of ~160ms. Mind you I was seeding about 100GiB of the most popular Linux ISOs on BitTorrent during this time.

      Hell, my state Uni has at least 1Tb/s of transit. At least 2 100Gb links to each of Level 3, Sprint, AT&T, Verizon, Hurricane Electric, possibly others that I'm not aware of. Not to mention another several 100Gb links spread to different regional IXs, and 100Gb peering links to local ISPs. This info is over 5 years old now. I'm sure they've increased their bandwidth since.

      Bandwidth is not expensive. Sonic.Net gave an interview where they said infrastructure and transit only represents 1%-2% of the cost of being an ISP. Your connection and the bandwidth it provides is a freaking rounding error on your bill and less than the sales tax. And that 1%-2% also includes maintaining and upgrading. Short of living in Alaska, national park, an island nation, or starting a new ISP, there is little reason for non-dedicated bandwidth.

  4. fast.com by Anonymous Coward · · Score: 5, Informative

    https://fast.com

    This site uses the same servers as the Netflix streaming service so it should be a clear indicator. You should note though that 3Mbps isnâ(TM)t very fast when it comes to playing streaming video. An HD stream from Netflix can easily hit 7 or 8 Mbps.

    1. Re:fast.com by Sarten-X · · Score: 5, Informative

      It's disappointing that this is currently scored 0. This is the right answer for this scenario.

      With strong Net Neutrality laws, there are limits to how sophisticated ISP throttling can be and still pretend to be legitimate. With that essentially eliminated now, the only meaningful test is to use actual traffic. Netflix has preempted this need for their own services by creating fast.com to look identical, going to Netflix servers over the same ports and protocols as normal Netflix traffic. It will be subject to the same throttling, and thus allows you to measure the speed you get when working with Netflix.

      I'd love to see other services hosting similar tools, but for now Netflix is the only major company I know of offering their own user-accessible performance test.

      --
      You do not have a moral or legal right to do absolutely anything you want.
    2. Re:fast.com by Athanasius · · Score: 4, Informative

      I was going to post fast.com if no-one else had.

      There's also a list of other tests on https://www.eff.org/testyouris...

  5. you can... by johnjones · · Score: 4, Informative

    its not that hard

    but you have to have at least two connections to compare the traffic

    a study that was funded by a USA national science award does exactly this :

    simply download a app and run it

    http://bit.ly/2IAdbmD

    you can thank me on twitter if you like http://twitter.com/johnjonesname

  6. Use the Netflix app speed test... by ambrose.carracho · · Score: 4, Informative

    Many devices allow you to check your connection speed within the Netflix app. (I would presume HBONow offers a similar utility.) The Netflix Page explaining how to do this is here: https://help.netflix.com/en/no.... On the same Netflix page are their internet download speed recommendations for playing TV shows and movies: 0.5 Megabits per second - Required broadband connection speed 1.5 Megabits per second - Recommended broadband connection speed 3.0 Megabits per second - Recommended for SD quality 5.0 Megabits per second - Recommended for HD quality 25 Megabits per second - Recommended for Ultra HD quality Remember that these figures are per stream, so concurrent streaming to multiple devices is bandwidth additive.

  7. Matt's TraceRoute by jrumney · · Score: 5, Informative

    A good way to find where a connection is being slowed is to use MTR, or on Windows WinMTR. It's a combination of ping and traceroute that can show where the network becomes slow, or error rates become high between you are the server you are using.

  8. Speed testing Comcast by meerling · · Score: 5, Interesting

    For many years I've tested my connection on comcast.
    If it's a popular or well publicized test site, comcast gives back great numbers.
    On the other hand, if you use any of the various ways to obfuscate the address, or just use one comcast doesn't have on it's script yet, then you'll see MUCH lower speeds.
    Yes, there are ways to verify that the obfuscation isn't causing the slowdown.

    Short version, comcast slows you down unless they know they're being tested, then they give you a higher bandwidth. I've tested them for close to 10 years now, and it's always the same.

  9. BS by PortHaven · · Score: 4, Insightful

    Comcast deliberately and specifically used to slow down Netflix traffic. Prior to Netflix paying them for peering.

    I had Comcast's 25mbps speed package, but couldn't stream Super or 3D content. Bandwith was too slow. Dropped my service down to 3mbps. Netflix and Comcast signed peering agreement. Suddenly, the very next day my 3mbps connection was fast enough to stream 3D content from Netflix.

    Ya....don't give me the congestion BS. The telcos very knowingly throttle certain content.