Re: [p2pi] Information in an ALTO protocol

> Nothing prevents an ISP to configure his ALTO server in order answer
to
identical requests using some form of statistical-balancing preference.

I would worry that the 'statistical balancing preference' could
alternatively viewed as 'ISP ALTO server is lying' or 'ISP ALTO server
prefers some applications over others'. I don't want to go there.

-- Rich

-----Original Message-----
From: stefano previdi [mailto:sprevidi@cisco.com] 
Sent: Friday, September 12, 2008 5:06 AM
To: Laird Popkin; Salman Abdul Baset
Cc: p2pi@ietf.org; Woundy, Richard
Subject: Re: [p2pi] Information in an ALTO protocol

> From: Laird Popkin <laird@pando.com>
> 
> (1) If an ISP configures their ALTO server to tell applications that
the
> users' uplink is less than it really is, I think that could have two
effects.
> For users inside the ISP, it would tend to suppress internal traffic
and cause
> peers to download from external peers, which is probably bad for the
ISP. And
> it might tend to cause peers from outside the ISP to shift traffic
elsewhere
> to some degree, which would reduce uplink utilization, which would be
an
> incentive to 'aim low'. How these two factors would balance out would
depend
> on the ISP's infrastructure.

... and on the ISP ALTO strategy.

Nothing prevents an ISP to configure his ALTO server in order answer to
identical requests using some form of statistical-balancing preference.

Multiple ISPs may want to cooperate by establishing ALTO policies among
their servers.

> (2) I don't believe that the p2p network would have to decide that the
ISP's
> ALTO server was 'lying'. P2P networks all currently measure observed
> throughput between peers and use that to make decisions. If they add
ALTO
> provisioning information, I would expect that they would treat
observed
> throughput as being more true than the ALTO guidance. So without
having to
> make a decision about 'ALTO lying' the p2p network would tend to take
> advantage of good ALTO guidance (because ALTO guidance and p2p
performance
> optimization reinforce each other) and would tend to cancel out bad
ALTO
> guidance (because the p2p performance optimization would end up
overruling the
> ALTO guidance).

I agree. What matters at the end of the day, is the measured
experience...

s.

> 
> - Laird Popkin, CTO, Pando Networks
>   mobile: 646/465-0570
> 
> ----- Original Message -----
> From: "Salman Abdul Baset" <sa2086@columbia.edu>
> To: "Laird Popkin" <laird@pando.com>
> Cc: "Richard Woundy" <Richard_Woundy@cable.comcast.com>, p2pi@ietf.org
> Sent: Thursday, September 11, 2008 3:46:10 PM (GMT-0500)
America/New_York
> Subject: Re: [p2pi] Information in an ALTO protocol
> 
> This raises at least two issues:
> 
>> Playing devil's advocate, while ALTO doesn't provide a mechanism for
ISP A
>> to tell non-customers anything, but it is possible for the p2p
network
>> as a whole to make decisions based on information provided by ALTO.
For
>> example, if ISP A says that its users have bad uplink, and ISP B says
>> that its customers have great uplink, then the rest of the internet
will
>> tend to download more from ISP B than A.
> 
> (1) Do ISPs have an incentive to lie to their customers that their
uplink
> is bad?
> 
> This will be counter-balanced
>> in that if, in practice, ISP A has fine uplink, the p2p network will
>> figure that out and use those peers anyway, ignoring the misleading
ALTO
>> guidance, because observed behavior has (IMO) more 'weight' than ALTO
>> guidance.
> 
> (2) Do P2P applications must determine if an ISP ALTO server is lying?
> 
> Note, that misconfiguration can also be a cause of ALTO server
providing
> misleading information.
> 
> -s
> 
> 
>> 
>> ----- Original Message -----
>> From: "Richard Woundy" <Richard_Woundy@cable.comcast.com>
>> To: "Reinaldo Penno" <rpenno@juniper.net>, "Laird Popkin"
<laird@pando.com>
>> Cc: p2pi@ietf.org
>> Sent: Thursday, September 11, 2008 2:52:06 PM (GMT-0500)
America/New_York
>> Subject: RE: [p2pi] Information in an ALTO protocol
>> 
>>> I was wondering if he was assuming some kind inter-ALTO
communication.
>> 
>> I guess I was. And perhaps Laird's points address my ISP traffic
>> management concerns -- I'm willing to concede.
>> 
>> Still worried about user privacy, though.
>> 
>> -- Rich
>> 
>> -----Original Message-----
>> From: p2pi-bounces@ietf.org [mailto:p2pi-bounces@ietf.org] On Behalf
Of
>> Reinaldo Penno
>> Sent: Thursday, September 11, 2008 2:31 PM
>> To: Laird Popkin; Woundy, Richard
>> Cc: p2pi@ietf.org
>> Subject: Re: [p2pi] Information in an ALTO protocol
>> 
>> That was going to be my observation to Rich's point as well. I was
>> wondering
>> if he was assuming some kind inter-ALTO communication. But even if
>> existed
>> it would not be Internet wide.
>> 
>> 
>> On 9/11/08 11:26 AM, "Laird Popkin" <laird@pando.com> wrote:
>> 
>>> The other issue is that ALTO is anticipated to be used by ISPs to
>> provide
>>> guidance to their own users. ALTO can't provide guidance to
customers
>> of other
>>> ISPs. So ISP A cannot tell the rest of the internet to pull data
from
>> ISP B
>>> but not ISP A.
>> 
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