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October 25, 2009

Is AT&T’s data overload self-inflicted?

Brough Turner summarizes and explains an hypothesis put forward by David Reed that much of AT&T’s bandwidth overload is self-inflicted.

As I understand it — which I admit is not very far — AT&T may have its servers misconfigured. If AT&T has set the servers’ buffers (particular servers — see Brough’s explanation) too large, then they disrupt the network’s traffic self-regulation loop. TCP increases its transmission rate until it starts losing packets. At that point, it cuts its transmission rate in half. So, if all those iPhones are transmitting packets that are being buffered instead of notifying the sending servers that they’re not being received, all those iPhones just keep increasing their transmission rates, further overloading the network.

Feel free to enumerate all the ways the following is wrong. I don’t claim to actually understand it. Here’s Brough’s summary:

It appears AT&T Wireless has configured their RNC buffers so there is no packet loss, i.e. with buffers capable of holding more than ten seconds of data. Zero packet loss may sound impressive to a telephone guy, but it causes TCP congestion collapse and thus doesn’t work for the mobile Internet!

If Reed’s hypothesis is correct, then presumably much of the congestion on AT&T’s network (but how much is much?) could be reduced by shrinking the buffers and allowing TCP to do the self-regulation it was designed to do.

:ATER: Brough’s article has been slashdotted.

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September 25, 2009

Broadband. Trust them.

At last, that brave band of oppressed companies who have been granted near-monopolies to deliver over-priced, under-performing broadband to the entire USA (exempting the parts they don’t find particularly profitable) have managed to scrape together an organization to give voice to their position. is finally going to air their views about why de-regulated near monopolies are the best and only way to bring affordable, open Internet to everyone in the country — views that until now have gone unheard, except from their hundreds and hundreds of lobbyists. Why, the industry could barely put together a mere $765,000 to send to John McCain’s campaign!

The site itself seems innocuous. Their history of the Internet nods in some appropriate directions, including to Al Gore and to students who have innovated on the Net. (It oddly leaves out Tim Berners-Lee.) Of course, it’s actually a paean to private industry that cleverly equates the role of creative individuals who have contributed mightily for free and the incumbent infrastructure providers whose financial incentives lead them to prefer to tilt the field against cash-starved start-ups. The closest the organization comes to stating its actual intent is in the wording of the print ad they’re running. Hmm. On the open medium of the Internet the organization hides its purpose, but in the controlled medium of print, they come close to stating it. How unexpected!

So, welcome to the Web, BroadbandForAmerica. Now — after your long list of rules of discussion, followed by a forum that is only soliciting happy stories — how about engaging in some honest, forthright discussion?

[Later that day:] Here’s a New Yorker interview with Julius Genachowski about Net Neutrality.


February 17, 2008

Phone company closed on Sundays

After trying the various phone numbers on the AT&T Wireless site, including 1-800-331-0500, 611 from my cellphone, and 800‑288‑2747 from, it seems that AT&T provides no customer service on Sunday. So, if your phone or their software is broken, you are SOL.

Jeez, remember when major corporations acted like major corporations? Or maybe this is how major corporations act.

(There’s gotta be a national security angle to this somewhere. Do terrorists and hurricanes take Sundays off? Yeah, that’s the ticket!) [Tags: ]