Re: [Dots] [core] WG Last Call on draft-ietf-core-new-block (No-Response)

"Christian M. Amsüss" <> Tue, 16 February 2021 23:53 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id D206D3A12FA; Tue, 16 Feb 2021 15:53:46 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.899
X-Spam-Status: No, score=-1.899 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id aVH1Dz7sHn2n; Tue, 16 Feb 2021 15:53:44 -0800 (PST)
Received: from ( [IPv6:2a01:4f8:190:3064::3]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 76EDF3A12F4; Tue, 16 Feb 2021 15:53:43 -0800 (PST)
Received: from ( []) by (Postfix) with ESMTPS id 0CCC740887; Wed, 17 Feb 2021 00:53:41 +0100 (CET)
Received: from ( [IPv6:2a02:b18:c13b:8010:a800:ff:fede:b1bf]) by (Postfix) with ESMTP id 1AACAFD; Wed, 17 Feb 2021 00:53:40 +0100 (CET)
Received: from ( [IPv6:2a02:b18:c13b:8010::aa6]) by (Postfix) with ESMTPSA id D720944; Wed, 17 Feb 2021 00:53:39 +0100 (CET)
Received: (nullmailer pid 612561 invoked by uid 1000); Tue, 16 Feb 2021 23:53:39 -0000
Date: Wed, 17 Feb 2021 00:53:39 +0100
From: Christian =?iso-8859-1?B?TS4gQW1z/HNz?= <>
Cc: "" <>, " WG (" <>, "" <>
Message-ID: <>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="HoBOzF5stQ3CqCEx"
Content-Disposition: inline
In-Reply-To: <23740_1612339780_601A5A44_23740_98_8_787AE7BB302AE849A7480A190F8B9330315C6374@OPEXCAUBMA2.corporate.adroot.infra.ftgroup> <28095_1608732578_5FE34FA2_28095_105_1_787AE7BB302AE849A7480A190F8B9330315A1C90@OPEXCAUBMA2.corporate.adroot.infra.ftgroup>
Archived-At: <>
Subject: Re: [Dots] [core] WG Last Call on draft-ietf-core-new-block (No-Response)
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "List for discussion of DDoS Open Threat Signaling \(DOTS\) technology and directions." <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Tue, 16 Feb 2021 23:53:47 -0000

Hello Med,

On Wed, Feb 03, 2021 at 08:09:40AM +0000, wrote:
> As a follow-up on this issue, we finally went with an approach that
> does not require No-Response. We do have the following to avoid extra
> delays, e.g., 

The need to indicate when a client wants confirmation has been avoided
by having timeouts on both sides, and relying more on MAX_PAYLOADS being

For my taste, that makes unnecessary sacrifices in robustness over the
simple two-byte NoResponse:0 that'd go with every MAX_PAYLOADS'th
Q-Block2 from the client (and would completey avoid the risk of stalling
in a lossless situation).

(For the other direction, corective heuristics can easily be applied).

But given they are explicitly configured in the DOTS case where Q-Block
is used, so -- well. Food for a block-bis (or generalized additions that
allow block to be used that way).

That aside, in the interest of readers who try to understand the
ecosystem and the trade-offs involved, I think that at least a reference
to it in a statement like "was not chosen because of X" would be
helpful. The "Note that similar performance benefits" section would lend
itself to that. Text suggestion:

  [messages are provided in Appendix A.] Similarly, The No-Response option
  can be applied to Block1 requests, but offers no corresponding facility
  for Block2 responses.


To use raw power is to make yourself infinitely vulnerable to greater powers.
  -- Bene Gesserit axiom