Re: [6tsch] minutes discussion models draft 1 October

[Qin Wang <[e-mail]>]

Xavi,

Agree!

Qin


On Wed, Oct 2, 2013 at 3:01 AM, Xavier Vilajosana Guillen <
[e-mail]> wrote:

> Hi Qin,
>
> I agree with you .. URI is to indentify the resource, i.e how do we access
> a particular service offered by the management layer, I agree that this
> should have CoAP name on it if this is bound to URI. then the data model(
> the content of what we sent on the payload) this should be generic right?
>
> so I see it in two separete things.
>
> 1-interaction model using CoAP
> 2-content/data model generic..
>
>
> X
>
>
>
>
> On Tue, Oct 1, 2013 at 11:56 AM, Qin Wang <[e-mail]> wrote:
>
>> Xavi and all,
>>
>> When we talk about data model (DM), there are likely several points of
>> view. For example:
>> (1) DM is a set of messages, their format, and the behavior caused by the
>> messages.
>> (2) Besides (1), also includes the interface with specific protocol, e.g.
>> URI in CoAP.
>>
>> From the point (1) of view, I agree Xavi. But, because URI is involved,
>> so, it becomes CoAP Data Model.
>>
>> So, can we separate the common part of DM, i.e. point (1) from protocol
>> specific part of DM, i.e. something like URI?
>>
>> What do you think?
>>
>> Qin
>>
>>
>>
>> On Wed, Oct 2, 2013 at 2:42 AM, Xavier Vilajosana Guillen <
>> [e-mail]> wrote:
>>
>>> HI all,
>>>
>>> I have a question raising from the minutes (sorry I could not connect
>>> today).
>>>
>>> If title of the draft is "6TiSCH CoAP data Model" this means that in the
>>> future we will have "6TiSCH *foo *data Model". Is that the direction we
>>> want? Data Model is the way to represent message content (i.e what goes in
>>> the payload and is used by 6top commands). Why is this specific to CoAP?
>>>
>>> Another aspect is interaction models, i.e message flows which in that
>>> case they are related to the capabilities of the transport mechanism.
>>>
>>> just thoughts..  Sorry if I really go back to something you already
>>> discussed and it is really clear.
>>>
>>> X
>>>
>>>
>>>
>>>
>>> On Tue, Oct 1, 2013 at 11:22 AM, Thomas Watteyne <
>>> [e-mail]> wrote:
>>>
>>>> All,
>>>>
>>>> You will find the minutes of the discussion about the models draft from
>>>> this morning at
>>>> https://bitbucket.org/6tsch/meetings/wiki/131001_webex_models_draft (also
>>>> copy-pasted below).
>>>>
>>>> Thomas
>>>>
>>>> ---
>>>>
>>>> Minutes Webex 1 October 2013, 6TiSCH group, models draft team
>>>>
>>>> Note: timestamps in PDT.
>>>> Taking notes *(using Etherpad)*
>>>>
>>>>    1. Thomas Watteyne
>>>>    2. Raghuram Sudhaakar
>>>>
>>>> Present *(alphabetically)*
>>>>
>>>>    1. Alaeddine Weslati
>>>>    2. Dan Romascanu
>>>>    3. Diego Dujovne
>>>>    4. Pascal Thubert
>>>>    5. Pouria Zand
>>>>    6. Qin Wang
>>>>    7. R. Nabati
>>>>    8. Raghuram Sudhaakar
>>>>    9. Thomas Watteyne
>>>>
>>>> Agenda
>>>>
>>>>    - Present pre-draft ToC *[Raghuram/Pouria]*
>>>>    - Discuss ToC
>>>>    - Define contents of each section
>>>>
>>>> Minutes
>>>>
>>>>    - *[08.05]* meeting starts.
>>>>    - *Raghuram* shares pre-draft through Webex
>>>>       - goals for today: define ToC, define contents of each section,
>>>>       pick title
>>>>       - Scope is to include data and interaction model for CoAP. At a
>>>>       later stage, extract information model as separate draft.
>>>>       - "6TiSCH data model" or "6TiSCH CoAP data model"?
>>>>    - *[Thomas]* personal opinion: have CoAP in title
>>>>    - *[Qin]* why interaction model on top of information model?
>>>>    - *[Raghuram]* we want to define message flows between PCE and
>>>>    nodes. Data model is exact definition of payload. We had rough consensus on
>>>>    using name-value pairs. Interaction model for CoAP or RSVP in future
>>>>    drafts. Interaction model provides abstract model of interaction between
>>>>    entities.
>>>>    - *[Qin]* RFC3444, interaction flows should be part of the data
>>>>    model? We should not conflict with RFC3444.
>>>>    - *[Thomas]* We may want to split the interaction from this (data
>>>>    model) draft.
>>>>    - *[Qin]* Data definition and coding is common part. For me,
>>>>    experience with different definitions. Don't want another terminology.
>>>>    - *[Dan]* Not extremely familiar with 6TiSCH but experience with
>>>>    data and information model. In the IETF, we have clear definitions about
>>>>    data and information model. RFC3444 accepted and used as reference. There
>>>>    are differences, i.e. interaction model. We need to stick with RFC3444 as
>>>>    close as possible.
>>>>    - *[Raghuram]* Goal of interaction model is try to extract
>>>>    information model at a later stage. CoAP is one of the transports we are
>>>>    using today, but we can use other protocol at a later stage. We can name it
>>>>    differently later "interaction method".
>>>>    - *[Dan]* If we are inventing a new name, it does not matter too
>>>>    much. We are looking at mapping different transports.
>>>>    - *[Raghuram]* Goal of interaction model is to extract the
>>>>    information model.
>>>>    - *[Raghuram]* Change to ToC: remove interaction?
>>>>    - *[Thomas]* Could be replaced by example scenarios.
>>>>    - *[Pascal]* We have identified interaction at L2, L3 and L5. We
>>>>    need to have discussion about the models.
>>>>    - *[Raghuram]* Conclusion: in ToC, new section 3.4 with "example
>>>>    interactions". Message formats would be moved up to 3.3, name-value pairs
>>>>    proposed.
>>>>    - *[Thomas]* Rough consensus?
>>>>    - *[Qin]* what's the different between management and informational
>>>>    resources?
>>>>    - *[Raghuram]* management resources are R/W, informational
>>>>    resources are R (e.g. DAGrank).
>>>>    - *[Thomas]* We could walk through ToC?
>>>>    - *[Raghuram]*
>>>>       - 3.1 naming convention for URI schemes. For example, root
>>>>       resource "6t". Includes naming convention for resources under root resource.
>>>>       - 3.2 resource of 6top we want to expose, i.e. management and
>>>>       informational resource.
>>>>       - 3.2.4 user installed resources, e.g. subscribe for particular
>>>>       implementation.
>>>>    - *[Raghuram]* Should we have extensible resources?
>>>>    - *[Thomas]* Yes.
>>>>    - *[Qin]* What the functional description of a resource? Related to
>>>>    not only management but also informational resources. Should we put every
>>>>    description attached to every resource? Looking at the content, I can
>>>>    imagine a resource list, with a description for each one. Suggestion is to
>>>>    put description just following the resource list.
>>>>    - *[Raghuram]* Fine with that.
>>>>    - *[Pouria]* Other change "functional description of resources"
>>>>    will fold into 3.2.1 and 3.2.2.
>>>>    - *[Raghuram]* Resource is just the URI, linked to particular 6top
>>>>    variable. Methods would fall under description of resource.
>>>>    - *[Qin]* Description of the MIB?
>>>>    - *[Raghuram]* End-user should be able to get a specific
>>>>    parameters. Returned as name-value pairs. If an entity wants the entire
>>>>    MIB, we will have a separate resource.
>>>>    - *[Thomas]* Mapping of 6top commands included?
>>>>    - *[Raghuram]* Yes. Mapping of table of 6top commands presented in
>>>>    previous calls.
>>>>    - *[Pouria]* In resource management, information that can be
>>>>    written by PCE, or commands to be executed.
>>>>    - *[Raghuram]* Everything that change the TSCH schedule falls under
>>>>    the management resource.
>>>>    - *[Raghuram]* Section 4 will be moved up. A message format will be
>>>>    attached to each URI.
>>>>    - *[Thomas]* Map the attributes from minimal draft and the commands
>>>>    from 6top draft.
>>>>    - *[Raghuram]* That is the plan.
>>>>    - *[Thomas]* What are extensions?
>>>>    - *[Raghuram]* We don't want to define the URI for every attribute,
>>>>    we want to enable people to install a new resource with a definition.
>>>>    - *[Raghuram]* In that context, what are profiles?
>>>>    - *[Thomas]* Profile is overarching modification to basic behavior:
>>>>    e.g. adding resources or adding method to existing resource.
>>>>    - *[Qin]* Understanding about profile: resource is fixed, behavior
>>>>    of resource can be configurable.
>>>>    - *[Pascal]* +1 it's very important we are able to do add to basic
>>>>    behavior.
>>>>    - *[Diego]* How can we describe a trigger, e.g. number of
>>>>    measurements to average over.
>>>>    - *[Thomas]* Do we have a solution?
>>>>    - *[Raghuram]* Yes, complex triggers are defined using well-known
>>>>    formats. RFC already defines how to encode several thresholds. Output would
>>>>    be sent on CoAP response or observe notification. One generic method for
>>>>    any kind of trigger.
>>>>    - *[Raghuram]* In profiles, modify or add behavior. Add is easy.
>>>>    Profiles as a way to define extra sets of complex triggers. Discovery. What
>>>>    we could express as profiles are extra complex triggers.
>>>>    - *[Thomas]* What are the next steps?
>>>>    - *[Raghuram]* Updated version of draft by next week to discuss
>>>>    progress. Invite contributors.
>>>>    - *[Thomas]* Name of draft?
>>>>    - *[Raghuram]* What about "6TiSCH CoAP data model".
>>>>    - *[Thomas]* We need to know editor to create repository.
>>>>    - *[Raghuram]* AOB?
>>>>
>>>>    No other business raised.
>>>>
>>>>    - *[09.05]* meeting ends.
>>>>
>>>>
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>