[Detnet] questions about draft-eckert-detnet-mpls-tc-tcqf

peng.shaofu@zte.com.cn Thu, 11 November 2021 07:00 UTC

Return-Path: <peng.shaofu@zte.com.cn>
X-Original-To: detnet@ietfa.amsl.com
Delivered-To: detnet@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 542793A0C97; Wed, 10 Nov 2021 23:00:29 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.9
X-Spam-Level:
X-Spam-Status: No, score=-1.9 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, UNPARSEABLE_RELAY=0.001] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id WKxChVt3Ajp8; Wed, 10 Nov 2021 23:00:27 -0800 (PST)
Received: from mxhk.zte.com.cn (mxhk.zte.com.cn [63.217.80.70]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 53D163A0C94; Wed, 10 Nov 2021 23:00:25 -0800 (PST)
Received: from mse-fl2.zte.com.cn (unknown [10.30.14.239]) by Forcepoint Email with ESMTPS id 3CFD6C88792E61C4E9CF; Thu, 11 Nov 2021 15:00:23 +0800 (CST)
Received: from njxapp03.zte.com.cn ([10.41.132.202]) by mse-fl2.zte.com.cn with SMTP id 1AB70BT0063528; Thu, 11 Nov 2021 15:00:11 +0800 (GMT-8) (envelope-from peng.shaofu@zte.com.cn)
Received: from mapi (njxapp05[null]) by mapi (Zmail) with MAPI id mid201; Thu, 11 Nov 2021 15:00:10 +0800 (CST)
Date: Thu, 11 Nov 2021 15:00:10 +0800 (CST)
X-Zmail-TransId: 2afd618cbf7a4ace7e06
X-Mailer: Zmail v1.0
Message-ID: <202111111500108747580@zte.com.cn>
Mime-Version: 1.0
From: <peng.shaofu@zte.com.cn>
To: <draft-eckert-detnet-mpls-tc-tcqf@ietf.org>
Cc: <detnet@ietf.org>
Content-Type: text/plain; charset="UTF-8"
X-MAIL: mse-fl2.zte.com.cn 1AB70BT0063528
Archived-At: <https://mailarchive.ietf.org/arch/msg/detnet/onDbiDXUVOXRepKyYc9HluNKvvo>
Subject: [Detnet] =?utf-8?q?questions_about_=C2=A0draft-eckert-detnet-mpl?= =?utf-8?q?s-tc-tcqf?=
X-BeenThere: detnet@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Discussions on Deterministic Networking BoF and Proposed WG <detnet.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/detnet>, <mailto:detnet-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/detnet/>
List-Post: <mailto:detnet@ietf.org>
List-Help: <mailto:detnet-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/detnet>, <mailto:detnet-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 11 Nov 2021 07:00:29 -0000

Hi authors,

Thanks for the effort to introduce TSN CQF to IP network, especially, a large scale WAN.

Can you help me to understand how does T-CQF solve the congestion ?  For example, an intermediate node with multiple incoming ports may receive T-CQF packets from many sources, and  these packets are put into the same cycle-id related queue. Can they be guaranteed to be sent together in the next cycle?  Appreciate for additional description of that in the document.

I have seen examples of single T-CQF flow competed with best-effor backgroup flows, that is OK. However, the competetion between multiple T-CQF flows may be more interesting.
One may say that there is a central controller to plan and arrange T-CQF flows, and never permit more T-CQF flows match the same local cycle-id at the intermediate node then to avoid congestion. I think that may be possible for a small network, but may be challange for large scale WAN.

Regards,
PSF