Re: [core] RD: Registration update/removal request without location

[Christer Holmberg <[e-mail]>]

Hi Christian,

One more thing.

>    What I understand you asking about is what would happen if the
>    registrant ignored the Location options but tries to perform the refresh
>    operation on the /rd resource:
>    
>      Req: POST /rd?ep=node1
>      (No payload)
>    
>      Res: 2.01 Created
>      Location: /reg/1234
>    
>    That can succeed on a CoAP level (depending on the precise handling of
>    absent content formats), but would not give the desired results: It is
>    interpreted as the registrant trying to create a new registration (to
>    override its previous one) *without any links in it* -- rather than
>    refreshing the existig registraion.
  
Maybe it would be good to point that out in the document?

Currently the draft says that the RD MUST return the location, but AFAIK there is no explicit MUST for the registrant to use it in updates (there is only a "must return the location that the registrant will later use in its updates" statement) will, so I think it would be good to make it more clear.

Thanks!

Regards,

Christer




  
    What a registrant that did not remember its location *could* do is to
    repeat the complete registration (copy-pasted from above):
    
      Req: POST /rd?ep=node1
      Payload:
      </hello>
    
      Res: 2.01 Created
      Location: /reg/1234
    
    which has the same effect as refreshing it -- but is less efficient, and
    not so much intended to be used like this. (That this is works this way
    at all is a result of making the registration operation idempotent to
    allow some optimizations, and to accomodate rebooting registrants). A
    client that can not be bothered to parse and remember the location
    should rather use the simple registration right away, which does allow
    more efficient operation.
    
    Does that answer your question?
    
    KR
    c
    
    -- 
    There's always a bigger fish.
      -- Qui-Gon Jinn