Re: [6lowapp] Next version of charter proposal up on 6lowapp.net

[Zach Shelby <[e-mail]>]

On Nov 5, 2009, at 18:03 , Kerry Lynn wrote:
>
> There seems to be a wide divergence of opinion on the meaning of
> "constrained", from full-on WS* to unable to contain any strings.  I  
> would
> offer a working definition, borrowed from Einstein, that CoNodes  
> should
> be "as simple as possible, but no simpler."

+1.

We are trying to enable the minimal features required by the targeted  
application domains, while integrating that with the web architecture  
the best we can. So I like your saying. Let me add another - "keep it  
simple, stupid".

>
> I believe that by moving as much functionality as possible from the
> CoNodes into the CoGII nodes, we end up with a lower total system cost
> and, ultimately, greater ubiquity. The definition of CoNode should  
> admit
> wired (e.g. power line connected) as well as wireless Devices.

Coogies (CoGII) are not required at all in the charter (nor should  
they be), in fact they are only necessary for interconnecting the CoAP  
framework with HTTP or other possible paradigms. CoAP is meant to work  
totally stand-alone between embedded devices, between devices and  
servers etc. So the goal is to keep it really simple, as we can't  
assume there is anywhere to move functionality to.

Now that said, there are useful things CoNodes (I kindof like that)  
may use a Coogie for, but those are performance improvements. For  
example you may cache profiles there.

>
> As a general approach to foster consensus, I'd suggest the WG might
> add to its "objectives and architecture" document a specification of
> which services must be present in a CoNode and which must be
> present in the CoGII node (and how the CoGII node differs from a
> ROLL node; e.g. where does header de/compression reside?)

Node speaking CoAP need to be totally autonomous, this is a must for  
these application areas. Coogies provide proxying to HTTP, possible  
caching for requests from the rest of the Internet etc.

Coogies operate at L5, and can be located just about anywhere. Sure,  
it may sometimes be running on the same device which operated as a  
LoWPAN Edge Router and/or LLN Border Router. More likely it is placed  
at the edge of the constrained domain, e.g. on the gateway router of  
the building automation IP network, or the AMI infrastructure etc.

Does that make sense from the charter? Ideas and making it more  
specific?

>
> I support the viewpoint that a collection of CoNodes should be able to
> implement some non-trivial applications without requiring a CoGII
> node (e.g. the "one light, one switch" scenario).  Others may disagree
> with this (perhaps even strongly) but I believe statements of this  
> sort
> will help focus the debate and lead to the the ultimate meaning of
> "constrained".
>
> I personally find it easier in the early stages to think in terms of  
> abstract
> services rather than specific protocols.  For example, "BACnet  
> relies on
> the ability to enumerate all the devices on the network and to query  
> the
> value of objects within a device."  The first is accomplished using  
> the
> "Who-is" or "Who-has" services (indeed, one might argue that having
> two such mechanisms runs counter to interoperability) while the second
> is accomplished using the "ReadProperty" service.  If we can reach
> consensus on which services we need then mapping to specific
> implementations might be easier.

Abstract services are what the charter is going after, we are not  
specifying how the protocol itself is to be realized yet.

>
> Lastly, might I suggest using in the charter "CoNet" in place of  
> "CNN"?

I get a TV feeling from CNN myself.... So you are thinking CoNode and  
CoNet?

Zach

>
> Respectfully submitted, Kerry Lynn
>
>
> On Thu, Nov 5, 2009 at 5:06 AM, Carsten Bormann <[e-mail]> wrote:
>> I have put a new version of the WG charter proposal on the wiki  
>> page at
>> http://6lowapp.net
>> =
>> http://trac.tools.ietf.org/area/app/trac/wiki/6LowApp
>> (charter text is at the end of the page).
>>
>> Obviously, I could not pick up every comment that was on the list  
>> (they were
>> partially going in conflicting directions), but please do comment  
>> on the new
>> version.
>>
>> Gruesse, Carsten
>>
>> _______________________________________________
>> 6lowapp mailing list
>> [e-mail]
>> https://www.ietf.org/mailman/listinfo/6lowapp
>>
> _______________________________________________
> 6lowapp mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/6lowapp

-- 
http://www.sensinode.com
http://zachshelby.org - My blog “On the Internet of Things”
Mobile: [phone]

Zach Shelby
Head of Research
Sensinode Ltd.
Kidekuja 2
88610 Vuokatti, FINLAND

This e-mail and all attached material are confidential and may contain  
legally privileged information. If you are not the intended recipient,  
please contact the sender and delete the e-mail from your system  
without producing, distributing or retaining copies thereof.