Subject: [homenet] A few more DNCP -06 nits and questions

From: Juliusz Chroboczek <[email-masked]>
Date: Sat, 27 Jun 2015 16:55:16 +0200

Markus,

Section 4.4 of -06 seems to say that Node Endpoint TLVs MUST be silently 
discarded.

Section 5, "containing data about the most recently sent RNS", should that 
be per interface ("endpoint")?  Since there's a distinct trickle instance 
per interface, this would make sense to me.

Since there's state shared between the Endpoint TLV and the other TLVs in 
a datagram, shouldn't you be requiring that the Endpoint TLV be sent first?

-- Juliusz

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From: Markus Stenberg <[email-masked]>
Date: Mon, 29 Jun 2015 18:15:39 +0300

> Section 4.4 of -06 seems to say that Node Endpoint TLVs MUST be silently

Not really, it is not unknown TLV as supporting it is required. However, 
wording deltas accepted if it makes it clearer.

> Section 5, "containing data about the most recently sent RNS", should
> that be per interface ("endpoint")?  Since there's a distinct trickle
> instance per interface, this would make sense to me.

It describes a minimal implementation (and that global counter covers 
the minimum needed RNS sending rate limiting). A possibly more 'correct' 
one would be e.g. tied to Trickle instances, which may be either per 
endpoint, or per (peer, local endpoint) in unicast case.

> Since there's state shared between the Endpoint TLV and the other TLVs
> in a datagram, shouldn't you be requiring that the Endpoint TLV be sent
> first?

We used to have a rather strict ordering of message contents (e.g. same 
as inside node data). It was not found desirable by reviewers. As a 
result of that, currently we do not force _any_ ordering.

I think you have a valid point here though; as the (datagram-case) 
packet processing can be made single pass given ordering constraint, it 
does make sense.

What do you think would be best here? Just specify that it MUST be 
before a Network State TLV within datagram? Or something more broad, 
like first TLV? (possibly too broad for future?)
Cheers,

-Markus