Re: [DNSOP] I-D Action: draft-ietf-dnsop-session-signal-03.txt

Ted Lemon <mellon@fugue.com> Tue, 11 July 2017 11:23 UTC

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From: Ted Lemon <mellon@fugue.com>
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Date: Tue, 11 Jul 2017 07:23:47 -0400
In-Reply-To: <89e8d29c-1692-732c-df3b-8b7915415629@nic.cz>
Cc: dnsop@ietf.org, Ondřej Surý <ondrej@sury.org>
To: Petr Špaček <petr.spacek@nic.cz>
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Subject: Re: [DNSOP] I-D Action: draft-ietf-dnsop-session-signal-03.txt
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On Jul 11, 2017, at 3:17 AM, Petr Špaček <petr.spacek@nic.cz> wrote:
> I feel that implications from switch to non-RR format are underestimated
> and following e-mail attempts to explain why I believe it is a bad idea.
> Please accept my apology for such long e-mail.

Petr, with all due respect, I did not see a counter-proposal here, and your comments seem to reflect a misunderstanding of what session-signaling is.

In fact, the opposite of what you said is true: if this were done as a normal query with EDNS0-like encapsulation, _then_ we would see problems, because session signaling messages would look more like DNS queries, and less like control messages.  This is not a desirable quality.

It's true that, for example, the DNS packet compression format would have to deal with this specially, but that would also be true if this were done EDNS0-style.   It's true that packet dumpers would have to deal with this specially, but that's also true if it's done EDNS0-style.   Etc.

It may be that there is a good point in your argument somewhere, but at the moment, I don't see one.   E.g., in your python example, yes, if this were an RR, not being able to plop it into your RR-handling switch would suck.   But it's not an RR, doesn't have the semantics of an RR, and if you plop it into your RR-handling switch, you're probably getting the semantics wrong.

So if you want to make this case, I think you need to be more specific about why this is a problem: when I think about how to implement this (which I have done, because I'm using it for dnssd), what you are advocating seems harder, not easier, than what is currently being proposed.