Re: [homenet] Kathleen Moriarty's Discuss on draft-ietf-homenet-hncp-09: (with DISCUSS)

Juliusz Chroboczek <> Wed, 18 November 2015 13:24 UTC

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Date: Wed, 18 Nov 2015 14:24:51 +0100
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From: Juliusz Chroboczek <>
To: "Kathleen Moriarty" <>
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Subject: Re: [homenet] Kathleen Moriarty's Discuss on draft-ietf-homenet-hncp-09: (with DISCUSS)
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Dear Kathleen,

> 2. Can you explain why DTLS is a SHOULD and not a MUST?  The bullet in
> section 3 reads as if this is for use, not implementation.  Is there a
> MUST for implementation (I didn't see one, but maybe I missed that)? 

I am not one of the authors of the draft, but I'm the author of the
independent reimplementation of HNCP (shncpd), so I have a fair
understanding of what the protocol does.

HNCP is an amazingly flexible protocol, and one that will hopefully be
used well beyond it's original area of application.  Many of the possible
applications of HNCP don't require DTLS, either because the network is
secured at a lower layer, or because they use a different application
layer mechanism.

To many people, a "Should Deploy, Must Implement" requirement in HNCP will
just seem like an arbitrary and useless hoop, and will needlessly reduce
the prestige and authority of the IETF.  If a MUST related to DTLS in
Homenet is required (and this is open to discussion), it belongs in
a different document, not in the HNCP protocol specification.


-- Juliusz