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:[email protected]]
*Sent:* vendredi 13 mai 2016 17:08
*To:* Pascal Thubert (pthubert) <[email protected]>
*Cc:* [email protected]; [email protected]
*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:
Ø4. 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.
Ø7. 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)
<[email protected] <mailto:[email protected]>>:
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.
Ø 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 fromSection 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?
Ø
Ø3.1. SF0 Triggering Events
Ø
Ø 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
Ø 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
Ø4. 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.
Ø7. Node Behavior at Boot
Again this is describing 6P not SF0 behavior. Note that the clear
should be done at link up in case
Ø11. Examples
Ø
Ø TODO
Ø
Ø12. Implementation Status
These sections probably belong to annexes
Cheers,
Pascal
_______________________________________________
6tisch mailing list
[email protected] <mailto:[email protected]>
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
[email protected]
https://www.ietf.org/mailman/listinfo/6tisch
_______________________________________________
6tisch mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/6tisch
