Re: [core] Robert Wilton's No Objection on draft-ietf-core-stateless-06: (with COMMENT)

[Klaus Hartke <[e-mail]>]

Robert Wilton wrote:
> Thanks for this document.  I found the document easy to read and the
> concept described easy to understand.

Thanks a lot for your review!

> 2.1 Extended Token Length (TKL) Field
>
>       13:  An 8-bit unsigned integer precedes the Token field and
>          indicates the length of the Token field minus 13.
>
>       14:  A 16-bit unsigned integer in network byte order precedes the
>          Token field and indicates the length of the Token field minus
>          269.
>
> I wonder whether it would be worth changing "precedes" to "directly
> precedes"
> to avoid any doubt of exactly where the length field appears?  Although I
> note that the updated message formats are in the appendix anyway.

I've changed "precedes" to "directly precedes".

> 2.2.1.  Extended-Token-Length Capability Option
>
>  The draft doesn't suggest whether the Extended-Token-Length capability
> option  should be used when the server only supports a max-length of 8.
> Would it be  useful to give a recommendation for servers in this case, e.g.
> SHOULD they  only include the capability if they support a max token length
> larger than 8  bytes?

IMHO it's already clear from RFC 8323 (which describes capability options in general) that the option does not need to be included if the base value is intended.

So, a good implementation would probably not include the option in this case, but there is no interoperability issue if it does that we'd need to prevent with a SHOULD (or MUST).

> 3.  Stateless Clients
>
>    As servers are just expected to return any token verbatim to the
>    client, this implementation strategy for clients does impact the
>    interoperability of client and server implementations.  However,
>    there are a number of significant, non-obvious implications (e.g.,
>    related to security and other CoAP protocol features) that client
>    implementations need take into consideration.
>
> I found the first sentence somewhat unclear - in that I was wondering if
> "does not impact" was intended instead of "does impact"?  Or otherwise, I
> wasn't quite sure what this sentence was trying to convey.

Good catch! "does not impact" is intended. Fixed.

Klaus