>-----Original Message----- >From: Laird Popkin [mailto:laird@xxxxxxxxx] >Sent: Tuesday, October 14, 2008 10:48 PM >To: Song Haibin >Subject: Re: [p2pi] WG Review: Application-Layer Traffic Optimization (alto) > >I'd like to second this, and also make sure that the relationship between ALTO >and the application is clear. > >From the application perspective, ALTO is a source of useful guidance (i.e. >network topology and "cost" model) that can help the p2p network find good peers >to connect. But once peers are exchanging data, the p2p network/protocol (and >TCP) pretty much takes over, because those protocols address the actual >throughput between peers, real-time congestion, etc., that are not addressed >by ALTO. > >I should also make clear that ALTO does not (and cannot) control the p2p network. >Generally ALTO guidance should provide better than average peer connections >(which is certainly what we saw in the P4P field tests), so the p2p networks >will be motivated to use ALTO guidance when they can because it's in their >interests to do so. But there will always be cases that are exceptions. For >example, if a p2p network is getting fantastic data delivery between two peers, >it is highly likely to keep using that connection no matter what ALTO says. And, >on the flip side, if the ALTO-recommended peer connections aren't providing the >data needed, the p2p network will use other peers as data sources. And, of course, >p2p networks must continue to operate where ALTO guidance is unavailable. :-) Yes, actually I have the same thought with you. BR Song Haibin >- Laird Popkin, CTO, Pando Networks > mobile: 646/465-0570 > >----- Original Message ----- >From: "Song Haibin" <melodysong@xxxxxxxxxx> >To: "Vijay K. Gurbani" <vkg@xxxxxxxxxxxxxxxxxx>, vidyan@xxxxxxxxxxxx >Cc: p2pi@xxxxxxxx, "IESG IESG" <iesg@xxxxxxxx>, ietf@xxxxxxxx >Sent: Tuesday, October 14, 2008 4:29:30 AM (GMT-0500) America/New_York >Subject: Re: [p2pi] WG Review: Application-Layer Traffic Optimization (alto) > >Hi Vijay, > >>Narayanan, Vidya wrote: >>> communications. In fact, all that is important in this context is >>> that the overlay acts as a rendezvous for sharing such information. >> >>I think the disconnect we may be having is that you view >>ALTO as a peer description protocol; it is not. Other >>protocols like BitTorrent, for example, are more suited to >>this, and they do exactly what you want. In a BitTorrent >>overlay (swarm), the overlay knows exactly which peer is >>contributing which content, which peer has which chunks, >>the download/upload ratio, the time the peer joined the swarm, >>whether the peer is choked or unchoked, whether the peer has >>a public port, etc. ALTO is not out to replace BitTorrent. What >>ALTO is providing are better strategies for peer selection. >> >>For instance, it is not ALTO that gets to decide which peer is >>hosting which content and what the contributions of that peer >>to the overlay are. However, it is ALTO's job to provide >>information to a querying peer allowing it to determine wisely >>where it will download the content from. > >Totally agree. > >>> I'm afraid that would be a mistake. It actually doesn't matter if we >>> don't agree today on the exact types of information that can be >>> shared. It is important that we have a protocol that allows peers to >>> publish ALTO related information. Having this protocol be >>> extensible would allow for any type of information to be carried in >>> it. >> >>So far, no one on the list has proposed that ALTO be a peer >>description and publication protocol. So based on the discussion >>we have had since (essentially the workshop in) May 2008 on the >>p2pi list, I would hesitate to add in the charter something that >>participants have not expressed any preference for (i.e., a >>deliverable on peers publishing their information.) > >IMHO, not every type of information can be carried in the ALTO protocol, but >only network policy and topology related (e.g. peer preference) information >is allowed. I don't think we are designing BitTorrent here. > >Regards! >Song Haibin > > >_______________________________________________ >p2pi mailing list >p2pi@xxxxxxxx >https://www.ietf.org/mailman/listinfo/p2pi _______________________________________________ Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf