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

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?

Comments

probably not slowing it specificly

[locopuyo]

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

Speed testing Comcast

[meerling]

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.

Re: Alternatively:

[silas_moeckel]

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.