Hi Qiao, Great thanks for your review. Please find my answers inline. Your questions stress the need for clarifications in the next draft version. Thanks, Sabine
De : alto [mailto:[email protected]] De la part de EXT Qiao Xiang Envoyé : mardi 1 mars 2016 21:45 À : Gao Kai; IETF ALTO Objet : Re: [alto] State of the WG Hi All, The following are my comments on draft-ietf-alto-multi-cost-01: Some typos: Sec 1, paragraph 5, "RTT" -> "Round Trip Time (RTT)" Sec 2, paragraph 2, "refering" -> "referring" Sec 2, move the abbreviation "Content Delivery Networks (CDN)" to the 2nd paragraph of Sec 1, where it appears in the draft for the first time. Sec 4.1.1, the paragraph of "multi-cost-types", second line: "thlis" -> "the" [SR ] Thanks for pointing the typos. Will be corrected in upcoming version Comments on testable-cost-types and multi-cost-types: I am a bit confused about "testable-cost-types". From the example in Sec 5.2, "cost-type" and "testable-cost-types" can coexist. [SR ] Do you refer to example #3 in section 5.4 ? And when they do, the constraint will be applied to "testable-cost-types". But from the description in paragraph 2 on page 10, it seems that if "multi-cost-types" exists, test will be applied only to "multi-cost-types", not "testable-cots-types". [SR ] If you refer in page 10/para 2 to the description of members "multi-cost-types" and “testable-cost-types” I don’t see what in the description implies this. There is an example on page 9 where both exist. But I understand a clearer formulation is needed. Would you please point in the text what makes you think this so that we can figure a better formulation? What if a client wants to get routingcost and delaycost when routingcost, delaycost and hopcount all satisfy certain constraints? In this case, there are two costs in "multi-cost-type", but three types of costs are desired to be tested. It seems the current design does not allow client to express a request like this. [SR ] the design actually does allow it and your example illustrate how input member "testable-cost-types" can be useful (see also example #3 section 5.4 page 18). In your example the request will have members "multi-cost-types" : [ {"cost-mode": "numerical", "cost-metric": "routingcost"}, {"cost-mode": "numerical", "cost-metric": "hopcount"} ], "testable-cost-types" : [ {"cost-mode": "numerical", "cost-metric": "routingcost"}, {"cost-mode": "numerical", "cost-metric": "hopcount"}, {"cost-mode": "numerical", "cost-metric": "delaycost"} ], with a "constraints" or "or-constraints" member which implies of course that the "cost-type-names" capability of the filtered Cost Map includes at least the names of the 3 listed “testable-cost-types”. It would be great if anyone could shed some lights on this issue. Thank you very much. [SR ] I hope my answers helped let me know if not. Best Qiao [SR ] Thanks Sabine On Tue, Feb 23, 2016 at 2:51 AM, Gao Kai <[email protected]<mailto:[email protected]>> wrote: Hi all, Below are my feedbacks on the multi-cost draft: Review on draft-ietf-alto-multi-cost-01: Notation: sec#X: Section X para#X: paragraph X line#X: line X ===== sec#1-para#1-line#3: Typo: "such" -> "such as" sec#1-para#7-line4: Typo: "definition" -> "definitions" sec#3.6: Instead of reusing the "constraints" field for "testable-cost-types", I'd like to propose that we enforce the use of "or-constraints". Firstly, the format of "testable-cost-types" is a list of cost types, but the "constraints" field is originally designed for testing one cost type. Even using the extended format, the conditions can only be concatenated by the AND operator. Using "or-constraints", on the other hand, provides better flexibility. Secondly, according to the draft, if the "testable-cost-types" is missing, the servers will test the "multi-cost-types" with the conditions specified by "or-constraints". Thus using "or-constraints" for both cases can simplify the implementation because the "constraints" field can be totally ignored in this case. Finally, from the example in section 5.4, I feel the extended usage of "constraints" seems to be only designed for the special case that the number of elements in "testable-cost-types" is 1, which I think the benefits are not worth the complexity it brings to both clients and servers. sec4.1.1-para#1: The type of "or-constraints" should be: [JSONArray or-constraints<0..*>;] sec4.1.1: In the description for "testable-cost-types", the first paragraph says it is described for the "constraints" parameter, which should be for the "or-constraints" parameter or, if we decide to reuse the "constraints" field, for both parameters. sec4.1.2: The description for "testable-cost-type-names" capability indicates it requires the "cost-constraints" capability to be "true". However, in that case, according to RFC 7285, all cost types should be able to be included in constraints, which means they are "testable". I cannot think of a good reason of doing that so my proposal is that we do the opposite: When the "cost-constraints" is set to "true", all types are testable and the "testable-cost-type-names" SHOULD NOT appear and MUST be omitted if it does. Otherwise, only the types specified in the "testable-cost-type-names" are considered testable. You thoughts and opinions are highly appreciated! Regards, Kai On 23/02/16 09:48, Gao Kai wrote: Hello Vijay and all, I can go through the WG drafts 2 and 3 (the SSE and Multi-cost) and give some feedbacks as soon as possible. Regards, Kai On 26/01/16 23:29, Vijay K. Gurbani wrote: Folks: The mailing list has been awfully quiet. Presently, we have 3 active I-Ds that are being tracked towards charter fulfillment: 1. draft-ietf-alto-deployments is in its second WGLC. The new WGLC ends on February 3, 2016. 2. draft-ietf-alto-incr-update-sse appears to be moving along and there do not seem to be any stop gap issues that we are aware of. Authors, please inform the WG if there are. 3. draft-ietf-alto-multi-cost is also fairly mature. It seems reasonable to move 2 and 3 ahead. Then there are a number of independent submissions dating back to Sep- Oct 2015 timeframe. These have not been updated and nor has there been much discussion on the mailing list. Some of these submissions are important for charter deliverables related to graph representation formats. Can the authors of the independent submissions kindly share what their plans are with respect to the drafts? This will help us gauge whether or not we should meet face-to-face in Buenos Aires or have an interim meeting before it and meet face-to-face in Berlin. Note that while the final plans are still up in the air and subject to change, there is a good chance that neither Jan or I will be able to make it to Buenos Aires. However, if a F2F meeting is desired, it is important to get a sense of the energy behind the independent drafts, as the list traffic has been woefully quiet on this front. Thanks, - vijay _______________________________________________ alto mailing list [email protected]<mailto:[email protected]> https://www.ietf.org/mailman/listinfo/alto _______________________________________________ alto mailing list [email protected]<mailto:[email protected]> https://www.ietf.org/mailman/listinfo/alto -- Qiao Xiang Postdoctoral Fellow, Department of Computer Science, Yale University
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