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| --- This message came from the IEEE 802.11 Task Group M Technical Reflector ---
Menzo/all, I have a couple concerns about the proposal in 11-20/0150r17 for CID 4761. But, I have to admit that I find the description of bit numbering/indexing in MAC addresses very confusing, so I’d be happy to be corrected. The first comment, is on the claim that we can assume multiple BSSID only acts on the last octet of the reference BSSID (the NOTE added in 9.4.2.45). 11-20/0150 claims this is true because “n has a maximum value of 8”, where there are a maximum of 2^n BSSIDs in the set, and then by reference to 9.4.2.73 concludes that n must be 8 or less. I see that logic. However, the definitive (normative) language for the Multiple BSSID set is in 11.10.14, which says, explicitly: “The size of the set is 2^n, for a selected value of n, 1 <= n <= 46.” So, we have a bit of a conflict, it seems. It is clear from 9.4.2.73 that the “BSSID Index” cannot be larger than 255. However, I can’t find any text that says the “i” that is used in 9.4.2.45 to derive the BSSID is the same value as the BSSID Index. Further, 9.4.2.45, where the BSSID derivation is detailed, does not seem to have any restriction on the value of i. It seems intuitive that “i” and the BSSID Index should be the same thing, but is it stated anywhere? And, what do we do about the conflict between 9.4.2.73 and 11.10.14 (that ensures we don’t break any existing implementations that might be relying on 11.10.14)? Second comment is a bit more subtle, and maybe I just live with it. But, I’m a little concerned about changing the definitions of dec() and A[b:c] such that there is no longer any mention of LSB and MSB. Clearly, the intention is that when doing a dec() operation, the correct/appropriate LSB and MSB should be applied, and the conversion done per that mapping. But, it no longer says that anywhere. So, in the few places that are left after your changes which use this function (all Partial AID related stuff, I think), we are trusting that everyone will understand how to interpret “dec(xxx[a:b])” correctly. I note that all these uses are always applied to MAC address (directly or indirectly), so maybe we can state that dec() only applies to bitstrings extracted from a MAC address, and therefore we can state the MSB/LSB behavior explicitly? It’s now completely de-coupled from the Multiple BSSID arithmetic, which frees us to define it quite narrowly and specifically, I think. Thanks. Mark To unsubscribe from the STDS-802-11-TGM list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-11-TGM&A=1 |