I like this view, Anand. Can we achieve that without getting complex?
Pascal From: S.V.R.Anand [mailto:an...@ece.iisc.ernet.in] Sent: jeudi 19 mai 2016 08:17 To: Pascal Thubert (pthubert) <pthub...@cisco.com>; Prof. Diego Dujovne <diego.dujo...@mail.udp.cl> Cc: 6tisch@ietf.org; draft-dujovne-6tisch-6top-...@tools.ietf.org Subject: Re: [6tisch] My adoption-time review of SFO Hi Pascal, I agree with your view. We certainly seem to require a service sub-layer that provides link layer abstraction by offering ways of obtaining links with desired properties that the user might want. For instance, the user might want to ask this sub-layer for a provision of desired number of links being made available at certain time intervals. The time intervals can be specified, say, in terms of delay bounds. One can use this link layer feature for several possible use cases, including (i) meeting delay requirements at coarse or fine grain level (ii) power savings (iii) improving data aggregation and so forth. The mapping of this requirement to precise cell management functionality will then be handled by the lower layer 6P and SF mechanisms. I am not sure how we can fit the above sub-layer in the current scheme of things. Let me know if I am making sense. Anand On Friday 13 May 2016 09:20 PM, Pascal Thubert (pthubert) wrote: Hell Diego, My point is that a SF should operate on a number of units of transmissions, which happen to be cells in our case. SF should indicate to 6top that there is a need to change for more of less of these units. But the fact that one of these units is mapped to a particular slot offset / channel offset should not be its business. I see it as a layer violation... What if for instance the SF is in the root? Should it really manage down to the cell? Pascal From: Prof. Diego Dujovne [mailto:diego.dujo...@mail.udp.cl] Sent: vendredi 13 mai 2016 17:08 To: Pascal Thubert (pthubert) <pthub...@cisco.com><mailto:pthub...@cisco.com> Cc: draft-dujovne-6tisch-6top-...@tools.ietf.org<mailto:draft-dujovne-6tisch-6top-...@tools.ietf.org>; 6tisch@ietf.org<mailto:6tisch@ietf.org> Subject: Re: [6tisch] My adoption-time review of SFO Dear all, During today's webex call, I presented a slide where the comments below were going to be addressed on the next version of the draft. However, I raised the point about: > 4. Rules for CellList Why is this here? Which cell are allocated is not SF0 's business, is it? OTOH, the semantics of the ADD that is mentioned should be somewhere, and I think, in this document. -> This section is recommended by the 6top-protocol draft, and AFAIK it defines which cells are offered and which are selected for allocation. > 7. Node Behavior at Boot Again this is describing 6P not SF0 behavior. Note that the clear should be done at link up in case -> This section is also recommended by the 6top-protocol draft, and it should include any type of pre-configuration and expected initial state on the SF. -> From the comment from Pascal on today's webex: "What if a node has a big storage and it can keep all configuration after a crash?" The SF can use that info to reconstruct all the configuration and recover instead of issuing a clear command. However, there must be a timeout period for recover; if this timeout expires, then all the cells from the crashed node shall be released. Rules for CellList and Node Behaviour at boot are recommended on Sec. 5.3 of draft-ietf-6tisch-6top- protocol-00 2016-04-18 13:48 GMT-03:00 Pascal Thubert (pthubert) <pthub...@cisco.com<mailto:pthub...@cisco.com>>: Dear authors: Please find my review of the SF0 draft; but since last call is pending please do not make *any* changes till after draft-ietf-*- 00 is published. > This document addresses the requirements for a scheduling function listed in [I-D.wang-6tisch-6top-sublayer<https://tools.ietf.org/html/draft-dujovne-6tisch-6top-sf0-01#ref-I-D.wang-6tisch-6top-sublayer>], Section 4.2, and follows the recommended outline from Section 4.3<https://tools.ietf.org/html/draft-dujovne-6tisch-6top-sf0-01#section-4.3>. I would expect that this doc is the reference for SF and is the one that requests the creation of the SF registry by IANA (text to be added in the IANA section). This reference to sublayer should go away since we are not promoting the draft at the moment - or should we be doing so? > > 3.1. SF0 Triggering Events > > We RECOMMEND SF0 to be triggered at least by the following events: The term 'We' is probably inappropriate. Better formulate this like " It is RECOMMENDED that..." Also shouldn't there be an event when: - Connectivity to the neighbor is lost. A L3 Link down event should free up resources. The question for 6P is how both sides agree at the same time that the link is down. - A threshold of unused time slots is reached so they should be freed > 6. If the RAB is less than the Minimum Remaining Bandwidth (MRB), Add MRB to the NOB: NOB=NOB+MRB Shouldn't this be NOB=MRB > 4. Rules for CellList Why is this here? Which cell are allocated is not SF0 's business, is it? OTOH, the semantics of the ADD that is mentioned should be somewhere, and I think, in this document. > 7. Node Behavior at Boot Again this is describing 6P not SF0 behavior. Note that the clear should be done at link up in case > 11. Examples > > TODO > > 12. Implementation Status These sections probably belong to annexes Cheers, Pascal _______________________________________________ 6tisch mailing list 6tisch@ietf.org<mailto:6tisch@ietf.org> https://www.ietf.org/mailman/listinfo/6tisch -- DIEGO DUJOVNE Académico Escuela de Ingeniería en Informática y Telecomunicaciones Facultad de Ingeniería UDP www.ingenieria.udp.cl<http://www.ingenieria.udp.cl> (56 2) 676 8125 _______________________________________________ 6tisch mailing list 6tisch@ietf.org<mailto:6tisch@ietf.org> https://www.ietf.org/mailman/listinfo/6tisch
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