Comcast and Net Speed Tests

JimDaGeek writes "I recently moved to Columbia, SC where I have Time Warner as my cable ISP and pay for an 8 Mbps connection and have been very happy with the service, speed, and reliability. In contrast I have heard bad things about Comcast. So now that I am up in the Philadelphia PA area visiting my parents, I decided to test out the speed and reliability using the Speakeasy speed test. The results surprised me. Here are the reported download speeds in Kbps: New York, 18,946; Washington, 15,821; Atlanta, 11,257; Chicago, 10,042; San Francisco, 4,230. What is going on? I know my father is not paying for a 10+ Mbps connection. Is Comcast giving priority to popular speed-test sites?" From Comcast's site, in the Philadelphia area they seem to offer download speeds of 6 or 8 Mbps, with an option for a "PowerBoost" to 12 Mbps on large files. This wouldn't explain the results JimDaGeek got of almost 19 Mbps down.

Update: 07/10 12:07 GMT by KD : A friend in Massachusetts had a tree fall on his house. The Comcast guy who reconnected the lines told him that they are boosting the line speed to 20 Mbps down / 2 Mbps up in certain areas to be more competitive with Verizon FiOS.

Comments

Time of day?

[carlivar]

Since cable bandwidth is shared, wouldn't the time of the test matter? I've noted (very unscientifically) that my Internet seems slower between roughly 7-9pm (on Charter in Los Angeles area).

Re:Time of day?

[catwh0re]

It also makes me think of how complicated the simple "bandwidth test" will be should net neutrality get thrown out the window.

Already we juggle the factors of location, "paid for speed", shared bandwidth issues with daytime or peak traffic.. but then without some kind of neutrality we'd also be juggling whether or not the interconnects between yourself and the test site are all on a higher priority or lower priority pipe.(something we could never know)

Today your ISP can blame a bit of the slowdowns on network conditions, but ultimately it's obvious if your ISP is a slower provider.. but in the future they'll be able to knowingly serve you slow speeds while claiming it's just the low-priority sites you may be visiting.

Re:Time of day?

[kaufmanmoore]

Facebook and myspace can eat bandwith with all the crap some people post.

Re:Time of day?

[lancejjj]

Since cable bandwidth is shared, wouldn't the time of the test matter? FYI, practically all internet traffic traverses shared communication lines. The point-to-point connection of DSL becomes shared as soon as your local copper pair is squeezed onto a multiplexed line, within a few thousand feet of your home.

Re:Time of day?

[ivan256]

Yes, and your cable connection uses a shared upstream connection once it reaches the CO too. The difference is that the "last-mile" connection is also shared. Either can become a bottleneck depending on traffic.

Of course the internet traverses shared lines. That's practically the point of the internet.

Why is this even being posted?

[Anonymous Coward]

Those are burstable rates, not sustained. The fact that this is even being posted on slashdot based on this ONE guys SINGLE speedtest using powerboost is kinda funny, shame on kdawson. Ask anyone in the DSL Reports forums, this is a joke if anyone is to take this seriously.

http://www.dslreports.com/forum/comcast

This is also an ad for Comcast, "OMG CRAZY FAST SPEEDS FOR SAME PRICE AS SLOWER SPEEDS!!", you just dont know it. Say basically, in one day, we have one post slamming Verizon for taking residents copper away and another praising Comcast for super fast speeds (Take that FIOS!!). Doesn't seem strange to anyone else?

Do It Yourself

[Doc Ruby]

The Speakeasy speed tests are indeed easy, and easy to "speak" about on their site with posted ratings. But there's nothing magic about it, that you couldn't do with simple commands from your PC.

All you've got to do is fire up a shell (whether Windows, Linux, or other client OS), and download a big (>10MB) file while timing it. Find an HTML link to a video or something, then download it from the shell (eg. wget or curl in Linux) to a local directory. Watch the minutes and seconds from when you first connect (right after you give the command, after you get the download feedback), to when the file is complete. Then examine (eg. ls on Linux, or use your GUI file manager) the file for its exact size in bytes, then divide the time by the size.

I know this seems obvious, but distrusting Speakeasy's numbers as cooked by Comcast shouldn't be the last act before punting to Slashdot. Real tests, not just examples like Speakeasy, are trivial to run by yourself.

Re:Giving Comcast Props

[Eric in SF]

Two things:

I have Comcast (8/768) in Cole Valley, San Francisco, and I have also noticed the speed increase. Uploads to my website are now cruising at 140kb/sec, occasionally dropping to 90kb/s. No complaints here! I performed a dslreports speed test recently and it also reported some Korean or Scandanavian-class bandwith numbers - the highest I've certainly ever seen in my time with broadband.

Second - it's my understanding that as you saturate the uplink connection (max out uploading a file) on a consumer-grade connection/router, you interrupt the normal control-channel "Chatter" of web browsing. Basically, the "I got it" packets are stuck due to the saturated uplink, and you don't get the next packet until the acknowledgement makes it.

I could be completely wrong - I am by no means a networking expert, so if this is wrong, be gentle.

Re:SpeedTest.net

[Anonymous Coward]

bandwidth != latency. You want both (high bandwidth and low latency, that is), but that doesn't make them equal.