Hi Richard,
Good comments. See inline. >"ISP doesn't need P2P operational details, which can reduce the risk of >disclosing P2P privacy." > > What "P2P operational details" do you envision are being sent to the ISP? In > P4P, no such information is delivered to the ISP -- it simply provides the > PID and pDistance Maps. What we talk about in the draft is compared to PROXIDOR or path rating. CPID solution is based on P4P. I also think P4P and CPID can get the same performance regarding the privacy issue, if ISP provides the PID and pDistance Maps in P4P. However, in terms of workload, especially in the case that a P2P client is an ALTO Client, I think using full map may cause some pressure to P2P client. Using CPID, we could obtain cost/pDistance by simple calculation without much searching or mapping cost. The way using full map here is a little inefficient than using CPID. >"Although the ISP topology information can be inferred by the full collection >of PIDs as P4P, a correct computational function or driver still need to be >obtained additionally to calculate the corresponding cost value." > > What prevents a set of peers (or even a single peer) from gathering the full > list of CPIDs, and simply computing the pairwise cost between each one? > Aren't the same costs that the ISP would have delivered in the pDistance > map immediately discovered by the P2P application? If so, what has the ISP > gained in terms of privacy? Both P4P and CPID can get pDistance map, one is a direct way and another is indirect by gathering the full list of CPIDs. P4P provides PID map and we can directly know relationships of IP-PID for all peers, but it is difficult to get an IP-CPID map because it needs to gather CPIDs for all peers. The results may be similar to some extend, but the required efforts are different. What do you think? Regards Yan _______________________________________________ alto mailing list [email protected] https://www.ietf.org/mailman/listinfo/alto
