Thomas,
From my point of view, regarding the dedicated/shared
discussion,
I vote for dedicated TX and RX.
I think the main goal of OTF is to dynamically manage bandwidth allocation
for data transmission purposes; then it is essential to guarantee that this
bandwidth is available with no contention. If contention is enabled (as in
shared cells), bandwidth access becomes statistic, then neither the
bandwidth
availability nor the delay can be guaranteed.
If OTF can also be used for management or non-priority traffic, that is,
what
I should call, real best-effort traffic, then shared cells can be an
option. As
far as I can remember, we have not considered specifically this type of
traffic
in our draft discussions to date.
So, I see three options:
-narrow the type of traffic to that requiring only dedicated cells,
-keep OTF traffic-agnostic,
-allow the upper layers (an application, for example) to send a
dedicated/shared flag
together with each bandwidth request. I think that a bandwidth request
accounting
service may be required in this case.
Any thoughts?
Diego
2015-05-10 22:54 GMT-03:00 Thomas Watteyne <[email protected]>:
> Diego,
> I agree with you that OTF is orthogonal to the flags, but I also believe
> we should be as precise as possible. Let's forget for a second in which
> draft what goes and think only about the end result. What flags would you
> put on the OTF cells, and would they be dedicated/shared? I have some weak
> opinion, but I'd love to hear your pros/cons.
> Thomas
>
>
> On Sunday, May 10, 2015, Prof. Diego Dujovne <[email protected]>
> wrote:
>
>> Thomas,
>> The only unknown here are the attributes supported
>> by the best-effort track. Since we are using best-effort, and
>> from the references I have cited, I think it must be specified
>> on the 6top draft whether dedicated (TX and RX) cells can
>> be used on the best-effort track. We have also replaced the
>> track references to bundle references, so it is clear OTF
>> is a L3 mechanism, so we specify now "best-effort bundle"
>> instead of "best-effort track".
>> AFAIK, we say nothing on the draft about the
>> cell attributes (shared, TX or RX), and we shall keep saying
>> nothing, since I think track and bundle attributes are outside
>> OTF scope.
>> Regards,
>>
>> Diego
>>
>>
>>
>>
>>
>>
>> 2015-05-10 1:52 GMT-03:00 Thomas Watteyne <[email protected]>:
>>
>>> Diego,
>>>
>>> I dont Fully understand what you are proposing, hence some clarifying
>>> questions.
>>>
>>> Currently, the OTF algorithm triggers when a node should schedule
>>> one cells TO its neighbor. Since all nodes run the OTF algorithm, the
>>> current node can also receive requests to schedule cells FROM any of its
>>> neighbors.
>>>
>>> Each cell is associated (this is not OTF specific):
>>> - one or more flags: TX, RX, SHARED
>>> - a neighbor, optional
>>> - a type: hard or soft
>>>
>>> What does the draft say now about the qualifiers, and what are you
>>> proposing to change those to?
>>>
>>> Thomas
>>>
>>>
>>> On Saturday, May 9, 2015, Prof. Diego Dujovne <[email protected]>
>>> wrote:
>>>
>>>> All,
>>>> Although we discussed briefly about this issue,
>>>> we did not arrive to a conclusion on this topic:
>>>>
>>>> "And I have not found requiring cells with specific link option (i.e.,
>>>> Tx only or Rx only). Is there any plan to add this feature into OTF? IMHO,
>>>> I think it may be useful to take advantage of TSCH that can make contention
>>>> free links between nodes. (From Jongsoo Jeong)"
>>>>
>>>> I do agree that with OTF we are working with bandwidth requests for
>>>> data traffic,
>>>> so dedicated TX or RX links should be preferred. I have not found any
>>>> specific restrictions on the link options available for the Best Effort
>>>> track which is the
>>>> one we are using for dynamic allocation. It is only mentioned on the
>>>> 6top sublayer draft as follows:
>>>>
>>>> If the TrackID is set to (0,0), the cell can be used by the best-
>>>> effort QoS configuration or as a Shared cell. If the TrackID is not
>>>> set to (0,0), i.e., the cell belongs to a specific track, the cell
>>>> MUST not be set as Shared cell.
>>>>
>>>> But it does not say that a best effort track MUST use Shared cells.
>>>>
>>>> We also discussed tracks for OTF in June 2014, but there were no
>>>> comments on
>>>> dedicated cells:
>>>>
>>>> http://www.ietf.org/mail-archive/web/6tisch/current/msg02335.html
>>>>
>>>> Any thoughts?
>>>>
>>>> Thanks,
>>>>
>>>> Diego
>>>>
>>>> --
>>>> DIEGO DUJOVNE
>>>> Académico Escuela de Ingeniería en Informática y Telecomunicaciones
>>>> Facultad de Ingeniería UDP
>>>> www.ingenieria.udp.cl
>>>> (56 2) 676 8125
>>>>
>>>
>>
>>
>> --
>> DIEGO DUJOVNE
>> Académico Escuela de Ingeniería en Informática y Telecomunicaciones
>> Facultad de Ingeniería UDP
>> www.ingenieria.udp.cl
>> (56 2) 676 8125
>>
>
--
DIEGO DUJOVNE
Académico Escuela de Ingeniería en Informática y Telecomunicaciones
Facultad de Ingeniería UDP
www.ingenieria.udp.cl
(56 2) 676 8125
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