1.3 Non-Normative References CoAP-OBSERVE

"1.3 Non-Normative References reads in part:

• • • • • 
          CoAP-OBSERVE Hartke, K., ""Observing Resources in CoAP"", IETF Internet-Draft 08, February 25, 2013

Found at: http://tools.ietf.org/search/draft-ietf-core-observe-08, expired: August 29, 2013.

As noted elsewhere:

• • • • • 
          Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as ""work in progress.""

This expired reference being in Non-Normative references does not save it because it is used normatively at 3.3 Observing Resources:

• • • • • 
          If an observed OBIX Object is updated a CoAP response message is sent to the client according to the CoAP-OBSERVE specification.

There is a later version of this draft, https://datatracker.ietf.org/doc/draft-ietf-core-observe/, due to expire April 18, 2014.

If an implementation conformed to version 8 of CoAP-OBSERVE, it would not conform to version 11 of CoAP-OBSERVE, as the change log clearly shows:

• • • • • 
          Changes from ietf-10 to ietf-11:

o Pointed out that client and server clocks may differ in their
realization of the SI second, and added robustness to the existing
reordering scheme by reducing the maximum notification rate to
32768 notifications per second (#341).

Changes from ietf-09 to ietf-10:

o Required consistent sequence numbers across requests (#333).

o Clarified that a server needs to update the entry in the list of
observers instead of adding a new entry if the endpoint/token pair
is already present.

o Allowed that a client uses a token that is currently in use to
ensure that it's still in the list of observers. This is possible
because sequence numbers are now consistent across requests and
servers won't add a new entry for the same token.

o Improved text on the transmission of non-confirmable notifications
to match Section 3.1.2 of RFC 5405 more closely.

o Updated examples to use UCUM units.

o Moved Appendix B into the introduction.

Changes from ietf-08 to ietf-09:

o Removed the side effects of requests on existing observations.
This includes removing that

• the client can use a GET request to cancel an observation;

• the server updates the entry in the list of observers instead
  of adding a new entry if the client is already present (#258,
  #281).

o Clarified that a resource (and hence an observation relationship)
is identified by the request options that are part of the Cache-
Key (#258).

o Clarified that a non-2.xx notification MUST NOT include an Observe
Option.

o Moved block-wise transfer of notifications to [I-D.ietf-core-
block].
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