Re: [p2pi] Information in an ALTO protocol

I don't disagree that you can measure a user's throughput, and in fact this is necessary for certain applications that negotiate codecs, eg iChat. But with speedtest servers and application-based measurement, there is an explicit or implicit opt-in by the user.

I suppose the ISP's ALTO service could also enable opt-in for the customer's provisioned speed to be reported, but I wonder how many customers would be incented to do this, and would that re-enforce any traffic concentration effects that I mentioned before (because few users opt in).

I suspect that knowing the link speed doesn't really enable the application to avoid testing for the actual available bandwidth, given that other applications may be consuming bandwidth.

-- Rich

----- Original Message -----
From: Laird Popkin <laird@pando.com>
To: Nicholas Weaver <nweaver@ICSI.Berkeley.EDU>
Cc: Nicholas Weaver <nweaver@ICSI.Berkeley.EDU>; Woundy, Richard; p2pi@ietf.org <p2pi@ietf.org>
Sent: Tue Aug 12 10:45:32 2008
Subject: Re: [p2pi] Information in an ALTO protocol

Many p2p networks already do this sort of thing, and I can't think of any way that the ISP could prevent it - any p2p app can measure throughput and report it. For example, see http://www.speedtest.net/global.php. Of course, this is only based on users that installed the agent, which may not be representative, and doesn't different between classes of users (since the agent can't tell whether they're on a DOCSIS 1/2/3 cable modem, etc.).

The advantage of getting link capacity info from the ISP rather than by measurement is that it's a bit faster and more consistent, and saves a little bandwidth by not doing the test.

The other alternative is to use commercial IP mapping databases (e.g. MaxMind's netspeed database), which is fast and cheap, but these databases not as accurate or precise as an ISP could be. For example, MaxMind differentiates between dial, broadband and corporate, but not between classes of broadband.

- Laird Popkin, CTO, Pando Networks
  mobile: 646/465-0570

----- Original Message -----
From: "Nicholas Weaver" <nweaver@ICSI.Berkeley.EDU>
To: "Laird Popkin" <laird@pando.com>
Cc: "Nicholas Weaver" <nweaver@ICSI.Berkeley.EDU>, "Richard Woundy" <Richard_Woundy@cable.comcast.com>, p2pi@ietf.org
Sent: Tuesday, August 12, 2008 10:28:03 AM (GMT-0500) America/New_York
Subject: Re: [p2pi] Information in an ALTO protocol

On Aug 12, 2008, at 7:12 AM, Laird Popkin wrote:

> Interesting points. I'm not paranoid enough. :-)

No, you're not.  Its not paranoia when they are out to get you.

> How about if this is exposed only to the ISP's customers?

My company-X P2P business model includes an agent I control on the  
user's computer, no?

So if its valuable, Company-X can use company-X's customers to mine  
the data.  This would especially be useful because you could do a  
direct increase in performance by feeding back the data to the  
tracking infrastructure.

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