I like the idea "I also appreciate there could be a dynamic role transferring mechanism between peer and client for one signal node regarding the changing environments." Is it similar to SIP's change a medium in the middle of a session? thanks, sherry ________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of longbwe longbwe Sent: Tuesday, February 10, 2009 3:41 AM To: Xiao, Lin (NSN - CN/Beijing) Cc: Wang, Sherry; [email protected]; Henry Sinnreich Subject: Re: [P2PSIP] mobile p2p in p2psip
Hi Xiao, Thanks for your thoughts! I also agree the distinctions between peer and client, for there could be heterogeneous devices in the overlay, we cannot assume only one role for all of them.You note that nodes may be devided into three categories:fixed,mobile and mixed, with the preferences that fixed nodes act peers and mobile nodes act clients.What if most nodes of the overlay are mobile and there are not enough fixed nodes running as peers?This is certainly becoming the case,with the emergences of more powerful and smarter mobile devices such as iPhone and GPhone, cell phones are functioning more like a small PC and young people will prefer their mobile phones to laptops. I also appreciate there could be a dynamic role transferring mechanism between peer and client for one singal node regarding the changing environments. On Tue, Feb 10, 2009 at 1:40 PM, Xiao, Lin (NSN - CN/Beijing) <[email protected]<mailto:[email protected]>> wrote: Hi Bruce and Haibin: I totally agree with you to further consider the mobility behavior together with the status of the node (peer or client) in the overlay. Mobility could bring disconnection and reconnection which changes the topology structure of a P2P overlay. Different influences are given to peers and clients. Clients only need to reconnect with overlay simply, while peers need do data migration and even more before changing connection. There is no point to ask client to install a same complex protocol with peer, especially in mobility scenario. Moreover, the frequent moving of peers could be a disaster for structured overlay. Therefore, it is necessary to tell which kind of devices could perform as peer and which should work as clients. Besides the peer/client definition mentioned in Reload base, the mobility character should also be considered to separate them. In my opinion, there could be three kinds of node in the overlay: fixed (e.g. desktop), mobile (e.g. handset) and mixed (e.g. laptop). Fixed nodes are obviously good candidates for peers of overlay, while mobile handsets should be limited in client status considering not only their limited capability and resources but also the highly mobile characteristic. Some devices like laptop could perform either as peers or as clients depending on requirement. The peer mobility issues are mainly brought by this kind of nodes. So, the overlay could be constructed by some relative static nodes as peers for data storage and message routing. The highly mobility nodes, which work only as clients, can not cause churn of the overlay topology structure. It seems that we'd better consider the client mobility and peer mobility separately to describe their behavior and to develop their protocols more clearly. Xiao Lin -----Original Message----- From: [email protected]<mailto:[email protected]> [mailto:[email protected]<mailto:[email protected]>] On Behalf Of ext Song Haibin Sent: Tuesday, February 10, 2009 9:54 AM To: 'Henry Sinnreich'; 'David Artu?edo Guillén'; 'Victor Pascual ávila' Cc: 'longbwe longbwe'; 'Wang,Sherry'; [email protected]<mailto:[email protected]> Subject: Re: [P2PSIP] mobile p2p in p2psip Hi Henry and Bin, >>Frequent changes has to be managed in order to route messages efficiently. >>It is not the same as churn, but it introduces similar challenges, IMHO. >>This makes sense and is the reason the present work in the P2P SIP WG >>we have peer nodes and client nodes. >There was an I-D (now expired) on this: >Pascual, V., Matuszewski, M., Shim, E., Zhang, H., and S. Yongchao, >"P2PSIP Clients", <draft-pascual-p2psip-clients> >It was preceded and followed by many discussions on this topic, such as >that frequent p2p protocol messages for peer nodes will quickly exhaust >the battery. As the co-author of this I-D (use my previous name Song Yongchao), I support that the mobile devices should be better to act as clients rather than peers whenever possible. But I guess there are scenarios where only mobile devices are available. In this case, more considerations need to be given to the mobility of a "peer". Bin, I don't know if this is what you concern about. BR Song Haibin Just to be clear, clients are a fully integrated component of the base reload protocol. Motivation for them and some discussion of related issues is in the p2psip-base appendix (and a much more extensive discussion in pascual-clients and others), but the actual mechanisms to support them should already be in the base draft. Discussion of further work identifying when a node should be a peer and when it should be a client, or overlay algorithms optimized for specific types of deployments, including "mobile", might be good topics for further work in new drafts, of course. Bruce _______________________________________________ P2PSIP mailing list [email protected]<mailto:[email protected]> https://www.ietf.org/mailman/listinfo/p2psip
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