[W3c WoT IG]: Review of "RESTful Design for Internet of Things Systems -draft"

Hi Ari,

I hope that the IETF meeting last week was successful.

As promised I have read your document: https://tools.ietf.org/html/draft-keranen-t2trg-rest-iot-00 and have a few comments. However, they may already be obsolete due to your discussions at the IETF meeting.


·        Section 3.1, Architecture:
Not sure on the distinction between Forward Proxy and Reverse Proxy. As far as I understand an example of a Reverse Proxy is a HTTP-CoAP GW. But could examples of Forward Proxies be given? What does this mean for IoT systems? In figure 3 it is stated that the Origin Server is "Legacy System" but I assume that it could also be a normal web server?


·        Section 3.5 HTTP and CoAP methods:
Would be fine with tangible examples on methods used in IoT use cases. I can guess the following for an "Assisted Living" device that uses sensors to detect a fall and also has a vibrator. The device uses HTTP or CoAP to communicate with an application cloud server.

Cloud server --> device:
PUT /startFallDetection      ---   as a new PUT does not change the state (fall being detected) if a previous PUT already has been issued.
POST /vibrate    ---    as each POST creates a new vibration.

Device -> cloud server:
POST /fallDetected  --- as it is send every time a fall occurs

Am I correct?


·        Section 3.5.3 PUT:
The sentence "Hence, the intent of PUT  is idempotent and visible to intermediaries, even though the exact effect is only known by the origin server." Does not seem correct if HTTPS or CoAPS is used. Then the message is not visible to intermediaries.


Best regards
  Claes

Claes Nilsson
Master Engineer - Web Research
Research&Incubation

Sony Mobile Communications
Tel: +46 70 55 66 878
claes1.nilsson@sonymobile.com<mailto:Firstname.Lastname@sonymobile.com>

sonymobile.com<http://sonymobile.com/>

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