Dear Malisa,

see my comments inline

Missatge de Mališa Vučinić <[email protected]> del dia dt., 17 de
jul. 2018 a les 17:57:

> Hi Xavi,
>
> Many thanks for sending this review. See my responses inline.
>
> Mališa
>
> On Fri, Jun 29, 2018 at 5:37 PM Xavi Vilajosana Guillen <
> [email protected]> wrote:
>
>> Hi,
>>
>> I reviewed the ”Minimal Security Framework for 6TiSCH” document.
>>
>> Here some comments that have not been mentioned by others.
>>
>> 1) I miss some section describing how errors are handled at the cbor
>> level. This is what if the received Configuration option is wrong, e.g
>> there is an element in the map with an unsupported value.
>> Or even what if the Join Request contains a wrong role number?. Would be
>> good to mention what are the actions taken by the JRC upon receiving a Join
>> Request with an incorrect CBOR element. Also from the
>> pledge point of view, what if the Join Response contains an unsupported
>> parameter. I guess the same will apply for Update Request, from the 6N
>> point of view.
>>
>
> This makes perfect sense. We focused on error handling in case security
> errors are detected on the OSCORE layer, and somehow neglected the
> parameter semantics.
>
> My proposal is to add a new CBOR parameter to CoJP objects, e.g.
> "error_code" carrying an array of errors codes that were detected.
>
> With that, we'd need to make a table of most common errors on the CoJP
> level.
>
> Does that make sense?
>

This makes sense. Maybe a concern is the length of the message which should
be kept small. Maybe we can discuss different options such a single error
byte (e.g., supporting 255 error codes) a bitmap or the proposed array of
errors.

>
>
>>
>> 2) The JRC is the origin of Parameter Update Requests which may contain
>> for example rekeying material or a new short address. The draft needs to
>> describe what happens if the destination 6N is not reachable.
>> I understand that there will be a timeout and possibly will retry later
>> or do not try anymore (this has to be stated).
>> What if the node is no more in the network? when the JRC will stop
>> sending the short address updates? When it will remove that node from its
>> "database"?
>>
>
> I discuss this also during the meeting tomorrow. What you propose is
> indeed something that an implementor must consider but I am not sure if we
> want to specify any particular behavior in the draft, since this seems to
> be more of a policy.
>
> I can add explicit text discussing this issue, but leaving it up to the
> implementation of the JRC to decide how transmission errors of CoAP CON
> message, that is Parameter Update Request, should be handled. What do you
> think?
>
> I think that identifying the issue is important so implementers can take
it into account.


>
>
>>
>> kind regards
>> Xavi
>> --
>> Dr. Xavier Vilajosana
>> Wireless Networks Lab
>>
>> *Internet Interdisciplinary Institute (IN3)Professor*
>> (+34) 646 633 681 <+34%20646%2063%2036%2081>
>> [email protected] <[email protected]>
>> http://xvilajosana.org
>> http://wine.rdi.uoc.edu
>> Parc Mediterrani de la Tecnologia
>> Av Carl Friedrich Gauss 5, B3 Building
>> 08860 Castelldefels (Barcelona). Catalonia. Spain
>> [image: Universitat Oberta de Catalunya]
>> ­
>> _______________________________________________
>> 6tisch mailing list
>> [email protected]
>> https://www.ietf.org/mailman/listinfo/6tisch
>>
>

-- 
Dr. Xavier Vilajosana
Wireless Networks Lab

*Internet Interdisciplinary Institute (IN3)Professor*
(+34) 646 633 681
[email protected] <[email protected]>
http://xvilajosana.org
http://wine.rdi.uoc.edu
Parc Mediterrani de la Tecnologia
Av Carl Friedrich Gauss 5, B3 Building
08860 Castelldefels (Barcelona). Catalonia. Spain
[image: Universitat Oberta de Catalunya]
­
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