Regarding resource: There will be classes of devices which currently will not support IP packets as the resource constraints are too high, e.g. self-powered switches where the power budget is so constrained you can barely get a squeak out of them. Do we want to accommodate these devices in CoRE etc.? Probably not, and so it makes sense to develop the network which suits those devices and proxy them on a gateway. On the other hand, I think we have established that we don't want to persistently continue to develop a plethora of coexisting but non-interoperating networks all connected to the internet through a hodge-podge of application gateways for the sake of it. This is the reality today and it could be argued that this has stifled the development of the highly-connected "Internet of Things" we have all been dreaming about; it is a solution but a clumsy one and one which doesn't scale well.
Regarding bandwidth: I remember back in the early 90's being able to look at basic websites over a V32.bis (14400 bps max.) modem; whilst the experience could be frustratingly slow, it was usable. And that was an online, interactive experience. So whilst we need to consider the arguments about bandwidth, I think that realistic traffic scenarios need to be carefully looked at before ruling some solutions out. I am sure there is already a plethora of experience from many of the contributors to this group who already work in this area.
So we come down to the limited ROM/RAM devices which sit uneasily between the clearly capable devices currently available and the very constrained and highly specific devices for certain types of network. Which way do we want to push them? On the basis that these are the devices which will become obsolete first, I would push them towards the constrained side and say they are all proxied. In which case, CoRE/ROLL/6LoWPAN becomes becomes focused on the more clearly capable devices and therefore, as said at the beginning of this e-mail, based on protocols taken verbatim where possible and adapted where necessary.
Robert Kris Pister wrote:
Richard -I think that today's things are being designed with wonderful chips like your Ember EM351 and EM357 which have 128kB and 192kB of flash and lots of RAM; like the Jennic JN5148, the Freescale MC13224, the Dust DN2510. They can run IP, they will run IP, and in many cases they do run IP. We all agree on that, and we're all excited about that. The debate centers on how many new protocols we need to invent, vs. how many we can adopt or adapt, with the existing hardware, and with an eye toward where technology trends are taking us. My concern, like yours, is over the rate of adoption. If the fastest path to broad adoption is to create new protocols for routing, ND, transport, and applications, then by all means let's do that. I'm concerned, however, that this has not been a uniformly successful approach for wireless sensor networks in the past. :) Many of us believe that we will see the fastest adoption by minimizing the number of new protocols. We might be wrong, and that's the debate.ksjp Richard Kelsey wrote:Date: Mon, 09 Nov 2009 22:12:03 -0800 From: Kris Pister <[email protected]> > Abandoning the installed base just goes to reinforce the idea > that IP isn't an appropriate technology for things.Michael - I think that we have the same goal, but I disagree with that statement. I think that re-writing every protocol from discovery through transport to applications, from scratch, is what reinforces the idea that IP isn't an appropriate technology for things.I realize that there are pressures from an installed base, but at this point it's a tiny fraction of the overall potential. If we let the 1% installed base dictate the path for the next 99%, we should do our best to ensure that it's the right path.Taking these two paragraphs together, you seem to be saying that IP is an appropriate technology for tomorrow's things, but not necessarily for today's. While the hardware will obviously improve over time, we still need to pick some target platform. The current 6lowpan charter gives 32K of flash as an example and mentions 802.15.4 repeatedly. Areyou suggesting that we recharter? The increasing capabilities of the hardware does give us thereassuring prospect that the longer we take the solve the problems the easier it will be to so. -Richard Kelsey_______________________________________________ 6lowapp mailing list [email protected] https://www.ietf.org/mailman/listinfo/6lowapp
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