Re: [p2pi] Information in an ALTO protocol
Laird Popkin <laird@pando.com> Thu, 11 September 2008 18:26 UTC
Return-Path: <p2pi-bounces@ietf.org>
X-Original-To: p2pi-archive@ietf.org
Delivered-To: ietfarch-p2pi-archive@core3.amsl.com
Received: from [127.0.0.1] (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id EC80D3A693C; Thu, 11 Sep 2008 11:26:47 -0700 (PDT)
X-Original-To: p2pi@core3.amsl.com
Delivered-To: p2pi@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 1DAFF3A693C for <p2pi@core3.amsl.com>; Thu, 11 Sep 2008 11:26:47 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -9.37
X-Spam-Level:
X-Spam-Status: No, score=-9.37 tagged_above=-999 required=5 tests=[AWL=-0.595, BAYES_05=-1.11, HABEAS_ACCREDITED_COI=-8, IP_NOT_FRIENDLY=0.334]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id L1xqhBmisCJ9 for <p2pi@core3.amsl.com>; Thu, 11 Sep 2008 11:26:42 -0700 (PDT)
Received: from dkny.pando.com (dkny.pando.com [67.99.55.163]) by core3.amsl.com (Postfix) with ESMTP id 782A73A67DF for <p2pi@ietf.org>; Thu, 11 Sep 2008 11:26:41 -0700 (PDT)
Received: from localhost (localhost.localdomain [127.0.0.1]) by dkny.pando.com (Postfix) with ESMTP id 91393E10C77; Thu, 11 Sep 2008 14:26:23 -0400 (EDT)
X-Virus-Scanned: amavisd-new at
Received: from dkny.pando.com ([127.0.0.1]) by localhost (dkny.pando.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 1FPzq64-1S3p; Thu, 11 Sep 2008 14:26:09 -0400 (EDT)
Received: from dkny.pando.com (dkny.pando.com [10.10.60.11]) by dkny.pando.com (Postfix) with ESMTP id 03F53E10C60; Thu, 11 Sep 2008 14:26:09 -0400 (EDT)
Date: Thu, 11 Sep 2008 14:26:08 -0400
From: Laird Popkin <laird@pando.com>
To: Richard Woundy <Richard_Woundy@cable.comcast.com>
Message-ID: <244110379.257691221157568965.JavaMail.root@dkny.pando.com>
In-Reply-To: <1146802062.257671221157453891.JavaMail.root@dkny.pando.com>
MIME-Version: 1.0
X-Originating-IP: [71.187.59.213]
Cc: p2pi@ietf.org
Subject: Re: [p2pi] Information in an ALTO protocol
X-BeenThere: p2pi@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: P2P Infrastructure Discussion <p2pi.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/p2pi>, <mailto:p2pi-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/pipermail/p2pi>
List-Post: <mailto:p2pi@ietf.org>
List-Help: <mailto:p2pi-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/p2pi>, <mailto:p2pi-request@ietf.org?subject=subscribe>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: p2pi-bounces@ietf.org
Errors-To: p2pi-bounces@ietf.org
Keep in mind that ALTO cannot control a p2p network, just provide guidance to it. P2P networks optimize for performance. So while an ISP might try to discourage use of peers on its network as seeds, the p2p network can freely ignore that guidance if they get better performance by using them anyway, as discovered through all of the other p2p mechanisms (tracker, DHT, PEX, etc.). 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. - Laird Popkin, CTO, Pando Networks mobile: 646/465-0570 ----- Original Message ----- From: "Richard Woundy" <Richard_Woundy@cable.comcast.com> To: "Reinaldo Penno" <rpenno@juniper.net>, "John Leslie" <john@jlc.net> Cc: p2pi@ietf.org Sent: Thursday, September 11, 2008 1:02:18 PM (GMT-0500) America/New_York Subject: Re: [p2pi] Information in an ALTO protocol >> If applications consistently chose ISP B customers over ISP A customers, that might double ISP B's application traffic and reduce ISP A's application traffic to zero... > It seems ISP A is still using the same bandwidth as before since all clients in it needs to download the whole file. The difference is that all those bits are coming from Inter-domain links. Maybe I am missing something here? Or maybe you mean ISP A's intra-domain traffic goes almost to zero. In this example, I meant that clients *outside* of ISP A and B would be incented to choose ISP B clients as peers, so ISP A's uploading to (non-ISP A) clients would drop to zero (in theory). So ISP A's outbound inter-domain traffic would go to zero (in theory). In practice -- it would depend on what optimization algorithm the ALTO client uses. I agree that ISP A clients would presumably download the same amount of content. And as Stas often reminds us, the aggregate amount of downloading has to equal the aggregate amount of uploading in any particular swarm. > I think this value could be easily exchange as part of PEX, the question is how a peer A would know if peer B is within his group of friends or not so he how much bandwidth will be available to him. Good question. It looks like Vuze already figured out a similar mechanism: http://faq.vuze.com/?View=entry&EntryID=239. :) >But then, of that theoretical available bandwidth, how much is available now and in the near future? I think there was a mile-long thread about measuring bw some time ago in this list. This was discussed on this list, and I understood that we agreed that real-time congestion information does NOT belong in an ALTO protocol. I am talking about allocation of the provisioned bandwidth for the customer, which is a far more static value. The provisioned bandwidth could be used by the client for helping to select a candidate peer list. It does not eliminate the need for measuring actual throughput and latency, which would be impacted by network congestion. -- Rich -----Original Message----- From: p2pi-bounces@ietf.org [mailto:p2pi-bounces@ietf.org] On Behalf Of Reinaldo Penno Sent: Tuesday, September 09, 2008 12:01 PM To: Woundy, Richard; John Leslie Cc: p2pi@ietf.org Subject: Re: [p2pi] Information in an ALTO protocol Hello, Few comments inline.. On 9/9/08 7:41 AM, "Woundy, Richard" <Richard_Woundy@cable.comcast.com> wrote: >>> and traffic concentration concern (traffic may be drawn to fewer ISP links >>> with premium customers). > >> I would hope that congestion would be noticed before this becomes a problem. > > Let me describe two edge cases to illustrate my concerns. Then, let me > describe one potential ALTO solution, and one potential non-ALTO solution. > > First, let's imagine an ISP that does not oversubscribe its broadband access > network, so ISP network congestion isn't an issue. This ISP hosts an ALTO > server that supplies its users' bandwidths. Further suppose, as an extreme > illustration, that this ISP has one premium customer with 10 Mbps upstream, > and lots of standard customers with 1 Mbps upstream. Wouldn't a typical > application instance in the Internet want to leverage this premium customer, > in preference to any of the other customers? And wouldn't that tend to funnel > much more application traffic to the network link of this premium user? And > maybe that concentration of application traffic is not in the best interests > of the premium customer? Maybe this would be another disincentive (besides > highere monthly subscription fees) to being a premium customer? > > Second, suppose there are two large ISPs of roughly the same size. Suppose > that ISP A provides customers with 10 Mbps upstream bandwidth, and ISP B > provides customers with 11 Mbps upstream bandwidth. Also assume that ISP B has > made a proportionally greater investment in its network (110%) than ISP A to > support the 11 Mbps upstream. Both ISPs host ALTO servers that supply their > respective users' bandwidths. If the typical application instance merely > compares the user bandwidth of an ISP A customer and an ISP B customer, it > would choose the 11 Mbps of the ISP B customer. If applications consistently > chose ISP B customers over ISP A customers, that might double ISP B's > application traffic and reduce ISP A's application traffic to zero. So ISP B's > greater investment in its infrastructure, and its transparency in its ALTO > service, is rewarded with far more application traffic (200%) than its > incremental investment (110%) justifies. It seems ISP A is still using the same bandwidth as before since all clients in it needs to download the whole file. The difference is that all those bits are coming from Inter-domain links. Maybe I am missing something here? Or maybe you mean ISP A's intra-domain traffic goes almost to zero. > > Having said this, there are solutions to these problems. One straightforward > solution is for the ALTO client to make a peer selection in a randomized way, > where the user bandwidth is another bias. For example, all other things being > equal between an ISP A customer and an ISP B customer, maybe the ISP B > customer is chosen 52.4% of the time, and the ISP A customer is chosen 47.6% > of the time, by a conforming ALTO client. That is, the likelihood of choosing > an ISP B customer is 10% higher than choosing an ISP A customer. > > But my preferred (non-ALTO) solution would be to have a simple access protocol > to obtain the available access bandwidth directly from the end host. Here is > my rationale: > > - The customer always controls whether any bandwidth information is shared at > all, and more importantly, with whom the information is shared. Thus, there is > no question about ISPs or third parties sharing this information without the > customer's permission. > > - The real value reported by this mechanism can be redefined to be "how much > of the customer's provisioned access bandwidth does the customer allow you to > use". As a customer, for example, I can choose to share proportionally more > bandwidth within my circle of friends than with strangers. I can choose to > share all of my bandwidth, or maybe to share only some of my bandwidth because > I anticipate needing some of my bandwidth in the future. These preferences may > be difficult to convey to the ISP or to a third party. > > The mechanism ought to allow for easy query by the application. If the > application can obtain this value fairly quickly, it can be used for the > interim selection of peers, prior to the application attempting to measure > available bandwidth by probing. Maybe this value could be communicated as part > of the initial transport exchange envisioned by the TANA group? I think this value could be easily exchange as part of PEX, the question is how a peer A would know if peer B is within his group of friends or not so he how much bandwidth will be available to him. But then, of that theoretical available bandwidth, how much is available now and in the near future? I think there was a mile-long thread about measuring bw some time ago in this list. > > -- Rich > > -----Original Message----- > From: p2pi-bounces@ietf.org [mailto:p2pi-bounces@ietf.org] On Behalf Of John > Leslie > Sent: Thursday, August 28, 2008 8:13 PM > To: Woundy, Richard > Cc: p2pi@ietf.org > Subject: Re: [p2pi] Information in an ALTO protocol > > Woundy, Richard <Richard_Woundy@cable.comcast.com> wrote: >> >>>> Hmmm ... so I suspect that it is premature to say that last-hop >>>> bandwidth is out of scope? What do others think? >> >>> For myself, I think we'd be silly to rule it out-of-scope because we >>> don't believe ISPs would agree to provide it. _Any_ question we ask an >>> ISP may well receive a "none-of-your-business" reply. >> >> I might be OK with leaving this in scope. I stated two potential ISP >> issues in a previous email: the marketing concern (the ISP may be >> revealing its mix of regular versus premium customers to competitors) > > This is certainly possible (in which case they won't answer, or will > answer with "noisy" data); but I don't think it would actually reveal > anything terribly useful. > >> and traffic concentration concern (traffic may be drawn to fewer ISP >> links with premium customers). > > I would hope that congestion would be noticed before this becomes > a problem. > >> My bigger concern, however, is the user privacy concern, about the ISP >> revealing to the general public about its premium/regular/economy >> customers. I agree that in many cases that this information may be >> actively measured, but that would seem to require at least some >> complicity by the end user (e.g. the end user's host needs to respond to >> the measurement traffic). > > Customers could legitimately object to this information being revealed. > >> So at least we should discuss whether a user opt-in or opt-out mechanism >> should be required for user-specific data like this. > > IMHO, that is best left for ISPs and customers to work out themselves. > > -- > John Leslie <john@jlc.net> > _______________________________________________ > p2pi mailing list > p2pi@ietf.org > https://www.ietf.org/mailman/listinfo/p2pi > > > _______________________________________________ > p2pi mailing list > p2pi@ietf.org > https://www.ietf.org/mailman/listinfo/p2pi _______________________________________________ p2pi mailing list p2pi@ietf.org https://www.ietf.org/mailman/listinfo/p2pi _______________________________________________ p2pi mailing list p2pi@ietf.org https://www.ietf.org/mailman/listinfo/p2pi _______________________________________________ p2pi mailing list p2pi@ietf.org https://www.ietf.org/mailman/listinfo/p2pi
- [p2pi] Information in an ALTO protocol Enrico Marocco
- Re: [p2pi] Information in an ALTO protocol Stanislav Shalunov
- Re: [p2pi] Information in an ALTO protocol Vinay Aggarwal
- Re: [p2pi] Information in an ALTO protocol Lars Eggert
- Re: [p2pi] Information in an ALTO protocol Laird Popkin
- Re: [p2pi] Information in an ALTO protocol chsoft
- Re: [p2pi] Information in an ALTO protocol Vinay Aggarwal
- Re: [p2pi] Information in an ALTO protocol Stanislav Shalunov
- Re: [p2pi] Information in an ALTO protocol Woundy, Richard
- Re: [p2pi] Information in an ALTO protocol Laird Popkin
- Re: [p2pi] Information in an ALTO protocol Nicholas Weaver
- Re: [p2pi] Information in an ALTO protocol Laird Popkin
- Re: [p2pi] Information in an ALTO protocol Woundy, Richard
- Re: [p2pi] Information in an ALTO protocol Sebastian Kiesel
- Re: [p2pi] Information in an ALTO protocol Stanislav Shalunov
- Re: [p2pi] Information in an ALTO protocol Fabio Hecht
- Re: [p2pi] Information in an ALTO protocol Song Haibin
- Re: [p2pi] Information in an ALTO protocol Vijay K. Gurbani
- Re: [p2pi] Information in an ALTO protocol David R Oran
- Re: [p2pi] Information in an ALTO protocol Spencer Dawkins
- Re: [p2pi] Information in an ALTO protocol Lisa Dusseault
- Re: [p2pi] Information in an ALTO protocol David R Oran
- Re: [p2pi] Information in an ALTO protocol Lisa Dusseault
- Re: [p2pi] Information in an ALTO protocol David R Oran
- Re: [p2pi] Information in an ALTO protocol Reinaldo Penno
- Re: [p2pi] Information in an ALTO protocol Lisa Dusseault
- Re: [p2pi] Information in an ALTO protocol Woundy, Richard
- Re: [p2pi] Information in an ALTO protocol Laird Popkin
- Re: [p2pi] Information in an ALTO protocol Laird Popkin
- Re: [p2pi] Information in an ALTO protocol Reinaldo Penno
- Re: [p2pi] Information in an ALTO protocol Woundy, Richard
- Re: [p2pi] Information in an ALTO protocol Laird Popkin
- Re: [p2pi] Information in an ALTO protocol Salman Abdul Baset
- Re: [p2pi] Information in an ALTO protocol Griffiths, Chris
- Re: [p2pi] Information in an ALTO protocol Laird Popkin
- Re: [p2pi] Information in an ALTO protocol stefano previdi
- Re: [p2pi] Information in an ALTO protocol Woundy, Richard
- Re: [p2pi] Information in an ALTO protocol stefano previdi
- Re: [p2pi] Information in an ALTO protocol Woundy, Richard
- Re: [p2pi] Information in an ALTO protocol stefano previdi
- Re: [p2pi] Information in an ALTO protocol Stanislav Shalunov
- Re: [p2pi] Information in an ALTO protocol Stanislav Shalunov
- Re: [p2pi] Information in an ALTO protocol Ye WANG
- Re: [p2pi] Information in an ALTO protocol Laird Popkin
- Re: [p2pi] Information in an ALTO protocol Nicholas Weaver
- Re: [p2pi] Information in an ALTO protocol Laird Popkin
- Re: [p2pi] Information in an ALTO protocol Nicholas Weaver
- Re: [p2pi] Information in an ALTO protocol Laird Popkin
- Re: [p2pi] Information in an ALTO protocol Philip Levis
- Re: [p2pi] Information in an ALTO protocol Stanislav Shalunov
- Re: [p2pi] Information in an ALTO protocol Stanislav Shalunov
- Re: [p2pi] Information in an ALTO protocol Laird Popkin
- Re: [p2pi] Information in an ALTO protocol Stanislav Shalunov
- Re: [p2pi] Information in an ALTO protocol Ye WANG
- Re: [p2pi] Information in an ALTO protocol The 8472
- Re: [p2pi] Information in an ALTO protocol Laird Popkin
- Re: [p2pi] Information in an ALTO protocol Salman Abdul Baset