Sorry for the fragmented review, but there are a couple of more issues: - The authors should do a review of all lower-case occurrences of must, should, may, and recommended. At least a few of them should be capitalized to indicate normative requirements.
- IMO, from a quick review, I-D.ietf-ippm-initial-registry as written is normative and should be listed as such. However, I think it would be better to simply refer to the actual registry ( https://www.iana.org/assignments/performance-metrics/performance-metrics.xhtml) rather than tie it to the initial entries. On Mon, Mar 29, 2021 at 5:30 PM Martin Duke <martin.h.d...@gmail.com> wrote: > One small correction: I'm jumping the gun on the author policy; 6 is > probably OK for now. > > On Mon, Mar 29, 2021 at 11:33 AM Martin Duke <martin.h.d...@gmail.com> > wrote: > >> Hello authors, >> >> Thank you very much for writing this draft. It is clearly a useful >> extension to ALTO and is quite clearly written, even to someone who is not >> a practitioner. I have numerous comments/questions and a few nits. >> >> These points are all invitations to discussion, rather than commands >> about what to change, as I've missed much of the WG deliberations that led >> to this text. >> >> COMMENTS: >> - There are six authors. Having more than 5 editors/authors listed on the >> front page requires strong justification and chair/AD approval. See the RFC >> Editor statement [1]. You are encouraged to designate a few editors for the >> front page and list as many authors as desired at the end. >> >> - Sec 2.1. The cost-source model is conceptually sound, but the >> justification for it seems underexplained. What exactly is a client going >> to do with this information? What different behaviors would a client >> execute if the context was e.g. "sla" instead of "nominal?" To the extent >> the parameters are not machine readable, like links to webpages, are we >> really expecting this information to be presented to the humans behind ALTO >> clients? >> >> - Sec 2.1 I am confused about the meaning of the "sla" cost-source. Does >> this refer to an SLA the ALTO client has with the network? Between the >> target IP and the network? Or something else? If the first, does this link >> to client authentication in some way? If the second, what are the privacy >> implications of exposing these SLAs? >> >> - Sec 2.1. Related to the above, the text suggests that any cost-source >> expressed as "import" could also be expressed as "estimation". Why would >> the server do this? The text should say, or perhaps it would be >> conceptually cleaner if "estimation" and "import" were mutually exclusive >> sources by definition. >> >> - Sec 3. I would prefer it if the parameters field in each of these >> definitions was a bit more strict. This relates to my confusion about >> machine-readable vs. human readable data; if this is meant to be >> machine-readable, then e.g. Sec 3.4.4 should be more specific in spelling >> out that the IGP protocols should be in a format with the RFC number, for >> instance. If it's to be human readable for a purpose I don't understand, >> then these looser definitions are probably OK. >> >> - Sec 3.4 Unlike the other metrics, I have no idea what a client is to do >> with the hop count metric, since clients don't care about hop count. Hops >> only affect users through delay and loss rate, which is present in other >> metrics. Is the intent here to provide a proxy for delay when direct delay >> information is not available? If so, we should say so. >> >> - Sec 5.3. I suggest a reword. >> >> OLD: >> To address this issue, the only defined "routingcost" metric can be >> only "estimation". >> >> NEW: >> To address this issue, if the "routingcost" metric contains a >> cost-context field, it MUST be "estimation." >> >> What should clients do if it's not "estimation?" Can they use it or >> reject the metric >> as malformed? >> >> - Sec 5.4.1: "...the ALTO server may provide the client with the validity >> period of the exposed metric values." >> >> Shouldn't there be a standard format for this? Or are you implying the >> use of cost-calendar? >> >> - Sec 5.4.2: I don't understand what this section is saying. Can the >> server provide new metrics not in the spec? Or is it saying that the server >> can take singletons about link one-way delays and compose path one-way and >> two-way delays, for example? >> >> NITS: >> - Sec 1. An initial sentence introducing ALTO at the beginning would be >> helpful, e.g. >> >> "ALTO [RFC 7285] provides a means for client to identify the most >> efficient information source when multiple copies of such information >> exist, by quering path information from an HTTP server." >> >> - Sec 2. The second paragraph is a little hard to read. Suggestion: >> >> OLD: >> >> On the other hand, to be able to use coarse-grained information such >> as routing system information (e.g., [RFC8571 >> <https://datatracker.ietf.org/doc/html/rfc8571>]), which may not >> provide fine-grained information such as (iii) Method of Measurement >> or Calculation and (vi) Measurement Timing, this document provides >> context information to indicate the source of information and hence >> available metric details. >> >> NEW: >> >> This document specifies context information to indicate the metric >> source, which can allow clients to obtain fine-grained information like >> (ii) Method of Measurement or Calculation and (vi) Measurement Timing." >> >> - Sec 2.1 In Fig. 1, please expand "NBI" on first use. >> >> - Sec 3.1.3 Expand "PID" on first use. >> >> - Sec 3.1.4 s/recommended/RECOMMENDED >> >> - Sec 3.4 s/metric hopcount/hopcount metric >> >> - Sec 4.1.3 would this be correct: s/give the throughput/give the maximum >> throughput >> >> - Sec 6. s/is a highly sensitive/is highly sensitive >> >> Thanks >> Martin >> >> [1] >> https://www.rfc-editor.org/pipermail/rfc-interest/2015-May/008869.html >> >
_______________________________________________ alto mailing list alto@ietf.org https://www.ietf.org/mailman/listinfo/alto
