Re: [T2TRG] T2TRG last call for draft-irtf-t2trg-iot-edge-06

[Carsten Bormann <[e-mail]>]

On 2022-05-30, at 21:38, Ari Keränen <ari.keranen=[e-mail]> wrote:
> 
> This is the RG last call for the draft "IoT Edge Challenges and Functions":
> https://datatracker.ietf.org/doc/draft-irtf-t2trg-iot-edge/

(No hat:)

I believe this document is almost ready to be published as a consensus
document of the T2TRG.

I already reviewed an earlier version of this document with a chair hat
on, but I have one question that came up while looking at the current
version, and a few more observations.

Grüße, Carsten


## Major

Of all things [sic], I have a question on your definition of Thing.

You seem to be defining "Thing" as follows:

   Things are usually embedded systems of various kinds, such as home
   appliances, mobile equipment, wearable devices, etc.  Things are
   widely distributed, but typically have limited storage and processing
   power, which raise concerns regarding reliability, performance,
   energy consumption, security, and privacy [Lin].  This limited
   storage and processing power leads to complementing IoT with cloud
   computing.

Please contrast this with (draft-ietf-asdf-sdf-11.txt):

   Thing:  A physical item that is also made available in the Internet
      of Things.  The term is used here for Things that are notable for
      their interaction with the physical world beyond interaction with
      humans; a temperature sensor or a light might be a Thing, but a
      router that employs both temperature sensors and indicator lights
      might exhibit less Thingness, as the effects of its functioning
      are mostly on the digital side.

Or (draft-irtf-t2trg-rest-iot-09.txt):

   Thing:  A physical item that is made available in the Internet of
      Things, thereby enabling digital interaction with the physical
      world for humans, services, and/or other Things.

The two latter definitions do not address constrainedness, so there is
a reason why these are different.  But two things stand out:

* You define Thing to be just the embedded system attached to a
  physical item, while the other two define the whole item to be the
  Thing.
* You seem to always associate constrainedness with Thingness; which
  makes one wonder whether your considerations apply to powerful
  Things, too.

You then also use terms such as end-device, endpoint.

## Minor

Outside time and frequency distribution, jitter is often a red herring
and 3.1 should talk about latency upper bounds.

I'm not sure I like service discovery being equated with "advertising
and consuming APIs" (4.1) -- not all services are described by an
"API".

In 4.3.2, I'm not sure whether you really want to cite
[I-D.ietf-core-oscore-groupcomm] or maybe
[I-D.ietf-core-groupcomm-bis].

In Section 5, I'm not sure how compression enters the security
considerations.

## Nits

I pushed some nits to https://github.com/t2trg/t2trg-iot-edge-computing/pull/16 as well.