Some comments inline. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Song Haibin Sent: Tuesday, February 10, 2009 6:22 PM To: 'Eric Burger' Cc: [email protected] Subject: Re: [alto] differences among applications
I don't like the idea to standardize the peer selection algorithms for each application either. But image that when ALTO server receives a request with a source peer and a destination peer list for peer selection, it responds the ranking information for each peer in the list. Here with different applications the ranking result may be different. I don't know if ALTO server must implement different peer selection algorithms internally for different applications, so that it can rank the candidates list. >>To enable this we need a way for an ALTO service to specify the metrics it >>can provide guidance on and a way for the application to select a metric of >>interest. Similar to P2PSIP, ALTO could have a alto service configuration >>document that provides such information. The p4p alto service could say that >>it supports the pDistance metric with a rating scale from 1 to X. Another >>alto service could use a different metric or multiple metrics. The >>application should have a way to specify the metric of interest. The ALTO >>service can then implement the peer selection which is just a ranking >>according to a metric it supports. It need not infer the application >>requirements. Or ALTO server does not need to understand the requirement of a specific application, surely, it can responds to queries with parameters, e.g. the ALTO server will not responds with the ranking info (generally a simple ranking info will take a lot of considerations into account), but just the topology information such as the routing hops from peer A to peer B is 5, peer A to peer C is 4, the link quality from peer A to peer B is "good", peer A to peer C is "fair", the economy cost..... And then with retrieval many types of information what the application needs, the application makes the choice. >>I think the para above is a good direction. However, it is not clear how to >>tag the ranking info with good enough information to allow the application to >>make a good selection. The ALTO service potentially should be able to cull >>the list of not useful peers if some of them do not satisfy some constraint >>in the query and not have to return all annotated ranking info back to the >>client. So my general confusion here is whether the ALTO server needs to understand the requirements of a specific application to do the peer selection. >>by requirement of a application if you mean the fact that an application can >>query for a metric of interest or specify a threshold (e.g. >128kbps), the >>ALTO server should likely be able to do this. It should not need to however >>infer the intent of the querying application i.e. giving a peer selection >>good for a p2p streaming application or good for a download service. The >>application should have to translate its needs to a standardized query >>supported by the ALTO server. Best Saumitra Best Regards, Haibin Email: [email protected] Skype: alexsonghw >-----Original Message----- >From: Eric Burger [mailto:[email protected]] >Sent: Tuesday, February 10, 2009 9:53 PM >To: Song Haibin >Cc: [email protected] >Subject: Re: [alto] differences among applications > >I would offer it is important to have the client specify what it >thinks is important. However, I would also offer it would be fatal to >have "Profile B", "Profile N", "Profile S" selection algorithms, where >B, N, and S are different applications. I will guarantee that by the >time we're done in the IETF, no one will case about those applications >and will have moved on to some other, hot applications. > >It may be worth noting what parameters are important. > >On Feb 10, 2009, at 7:25 AM, stefano previdi wrote: > >> >> On Feb 10, 2009, at 12:43 PM, Song Haibin wrote: >> >>> I think it is necessary to discuss whether we need to standardize >>> different >>> peer selection algorithms according to different types of >>> applications. >> >> We may want the alto protocol to allow the requester to specify >> which type of ranking/preference it needs. Note that this doesn't >> mean we need to standardize any algorithm. >> >> s. >> >>> >>> Best Regards, >>> Haibin >>> Email: [email protected] >>> Skype: alexsonghw >>> >>> >>>> -----Original Message----- >>>> From: [email protected] [mailto:[email protected]] On >>>> Behalf Of >>> Enrico >>>> Marocco >>>> Sent: Tuesday, February 10, 2009 7:16 PM >>>> To: Zoran Despotovic >>>> Cc: [email protected] >>>> Subject: Re: [alto] differences among applications >>>> >>>> Zoran Despotovic wrote: >>>>> I was wondering if and how IETF would address possible >>>>> differences among >>>>> relevant P2P applications in the sense that different >>>>> applications may >>>>> require totally different solutions. Was there any discussion on >>>>> this >>>>> before on the list? >>>> >>>> Yes, there's been some discussion about how to deal with the fact >>>> that >>>> different applications may have different requirements for peer >>>> selection -- e.g. file-sharing would benefit most from connections >>>> to >>>> peers with higher uplink bandwidth, while realtime communications >>>> applications would probably want to chose media relays with the >>>> smallest >>>> delay. >>>> >>>> I remember someone suggested that a way to address it could be to >>>> simply >>>> provide a means for the querying peer to specify what parameters it >>>> would like to have optimized (delay, bandwidth...) and let the ALTO >>>> server use such information in its processing. However, AFAIK, no >>>> solution proposals at this time do anything like that. >>>> >>>> -- >>>> Ciao, >>>> Enrico >>> >>> _______________________________________________ >>> alto mailing list >>> [email protected] >>> https://www.ietf.org/mailman/listinfo/alto >> >> _______________________________________________ >> alto mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/alto _______________________________________________ alto mailing list [email protected] https://www.ietf.org/mailman/listinfo/alto _______________________________________________ alto mailing list [email protected] https://www.ietf.org/mailman/listinfo/alto
