Re: [Bier] BIER: draft-eckert-bier-cgm2-rbs-01 with performance analysis simulation

zhang.zheng@zte.com.cn Thu, 10 February 2022 01:17 UTC

Return-Path: <zhang.zheng@zte.com.cn>
X-Original-To: bier@ietfa.amsl.com
Delivered-To: bier@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C45223A1084 for <bier@ietfa.amsl.com>; Wed, 9 Feb 2022 17:17:17 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.895
X-Spam-Level:
X-Spam-Status: No, score=-1.895 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, CTE_8BIT_MISMATCH=0.001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, UNPARSEABLE_RELAY=0.001, URIBL_BLOCKED=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 0_RKrmQggASi for <bier@ietfa.amsl.com>; Wed, 9 Feb 2022 17:17:12 -0800 (PST)
Received: from mxhk.zte.com.cn (mxhk.zte.com.cn [63.216.63.40]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 0F6F73A1068 for <bier@ietf.org>; Wed, 9 Feb 2022 17:17:11 -0800 (PST)
Received: from mxct.zte.com.cn (unknown [192.168.251.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mxhk.zte.com.cn (FangMail) with ESMTPS id 4JvJkZ1kMZz8PxCr for <bier@ietf.org>; Thu, 10 Feb 2022 09:17:10 +0800 (CST)
Received: from mse-fl2.zte.com.cn (unknown [10.30.14.239]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mxct.zte.com.cn (FangMail) with ESMTPS id 4JvJjz2QX3z501bH; Thu, 10 Feb 2022 09:16:39 +0800 (CST)
Received: from njxapp03.zte.com.cn ([10.41.132.202]) by mse-fl2.zte.com.cn with SMTP id 21A1GSPi004798; Thu, 10 Feb 2022 09:16:28 +0800 (GMT-8) (envelope-from zhang.zheng@zte.com.cn)
Received: from mapi (njxapp01[null]) by mapi (Zmail) with MAPI id mid203; Thu, 10 Feb 2022 09:16:28 +0800 (CST)
Date: Thu, 10 Feb 2022 09:16:28 +0800
X-Zmail-TransId: 2af96204676c29b771e8
X-Mailer: Zmail v1.0
Message-ID: <202202100916283995253@zte.com.cn>
In-Reply-To: <BL0PR05MB5652537CC10FDCE8DACE5B6DD42E9@BL0PR05MB5652.namprd05.prod.outlook.com>
References: YgQTlG4sgMM+cFPG@faui48e.informatik.uni-erlangen.de, BL0PR05MB5652537CC10FDCE8DACE5B6DD42E9@BL0PR05MB5652.namprd05.prod.outlook.com
Mime-Version: 1.0
From: zhang.zheng@zte.com.cn
To: tte@cs.fau.de
Cc: bier@ietf.org, bing.xu@huawei.com, zzhang=40juniper.net@dmarc.ietf.org
Content-Type: text/plain; charset="UTF-8"
X-MAIL: mse-fl2.zte.com.cn 21A1GSPi004798
X-Fangmail-Gw-Spam-Type: 0
X-FangMail-Miltered: at cgslv5.04-192.168.250.137.novalocal with ID 62046796.000 by FangMail milter!
X-FangMail-Envelope: 1644455830/4JvJkZ1kMZz8PxCr/62046796.000/192.168.251.13/[192.168.251.13]/mxct.zte.com.cn/<zhang.zheng@zte.com.cn>
X-Fangmail-Anti-Spam-Filtered: true
X-Fangmail-MID-QID: 62046796.000/4JvJkZ1kMZz8PxCr
Archived-At: <https://mailarchive.ietf.org/arch/msg/bier/u5rnlgFYY5JzFerJyEwh1-lRfcs>
Subject: Re: [Bier] BIER: draft-eckert-bier-cgm2-rbs-01 with performance analysis simulation
X-BeenThere: bier@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "\"Bit Indexed Explicit Replication discussion list\"" <bier.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/bier>, <mailto:bier-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/bier/>
List-Post: <mailto:bier@ietf.org>
List-Help: <mailto:bier-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/bier>, <mailto:bier-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 10 Feb 2022 01:17:18 -0000

Hi Toerless, 
Haven't read the new version of CGM2/RBS, just have the same question with Jeffrey. 
If I understand BIER-TE and CGM2/RBS solutions right, the forwarding tables of the two methods are only focus on the local links. 
So the table's scale for the two solutions is almost same. 
The commen issue of the two solution is the BSL limitation. 
BIER-TE solution has an exclusive issue that the BP needs to be assigned globally. 
But in CGM2/RBS solution, the BP needs not to be assigned globally. 
So the main difference of the two solutions is: is it necessary to assign the BP globally, right?
Best regards,
Sandy


------------------原始邮件------------------
发件人:Jeffrey(Zhaohui)Zhang
收件人:tte@cs.fau.de;bier@ietf.org;
抄送人:bing.xu@huawei.com;
日 期 :2022年02月10日 04:50
主 题 :Re: [Bier] BIER: draft-eckert-bier-cgm2-rbs-01 with performance analysis simulation
Hi Toerless,
Not sure if my understanding is correct, but it seems that RBS does not reduce the number of bits that are needed to encode the tree. Rather, it increases the number of bits (to encode the recursive structure).
I agree that it reduces the size of BIFTs, but even current BIER-TE can reduce the number of copies if you use a longer bitstring?
Jeffrey
Juniper Business Use Only
-----Original Message-----
From: BIER <bier-bounces@ietf.org> On Behalf Of tte@cs.fau.de
Sent: Wednesday, February 9, 2022 2:19 PM
To: bier@ietf.org
Cc: bing.xu@huawei.com
Subject: [Bier] BIER: draft-eckert-bier-cgm2-rbs-01 with performance analysis simulation
[External Email. Be cautious of content]
Dear BIER-TE WG:
Robin did add a section (6.3) describing an initial performance gain analysis of CGM2/RBS to the github source (https://urldefense.com/v3/__https://github.com/toerless/bier-cgm2-rbs__;!!NEt6yMaO-gk!WS49OT72vlonSWP3yLtLcW_RQARYP00KEiAWpH592AuDXmrOOJH_bgVzQZyfK9En$ ), and i just did a bit of editorial fixup and posted it as -01 of the draft.
This actually is the first time i actually like the HTML'ized version of a draft, because the topology picture is so large it doesn't fit a single page:
https://urldefense.com/v3/__https://www.ietf.org/archive/id/draft-eckert-bier-cgm2-rbs-01.html__;!!NEt6yMaO-gk!WS49OT72vlonSWP3yLtLcW_RQARYP00KEiAWpH592AuDXmrOOJH_bgVzQaBIgBPC$
The interesting piece about the comparison is that it is actually comparing CGM2/RBS to BIER, and not BIER-TE. Because BIER itself should be requiring less copies than BIER-TE, so the gain of CGM2/RBS over BIER-TE should be even higher, but the fact alone that you get away with fewer packet copies to large receiver sets even though the bitstring also needs to encode the path/tree towards the receivers is really cool.
Robin, two Q:
1. The new text mentions "in our graphs", but the text does not include any such graphs (yet).
I guess such a graph would be even worse to convert to ASCII than the topology.
Maybe post whatever format you have those results in to github (PDF, png...) and then we actually may want to see if/how a PDF version of the draft could include better than just ASCII art. Certainly a good reason to finally try it out.
And short term we can just add references to such visuals to the draft.
2; Is it correct to assume that the hops through the topology that you simulated are "just" shortest-path, maybe with some ECMP choice - aka: the same paths that also BIER would choose given some "default" IGP routing setup ?
Cheers
Toerless
_______________________________________________
BIER mailing list
BIER@ietf.org
https://urldefense.com/v3/__https://www.ietf.org/mailman/listinfo/bier__;!!NEt6yMaO-gk!WS49OT72vlonSWP3yLtLcW_RQARYP00KEiAWpH592AuDXmrOOJH_bgVzQZXGUd9P$
_______________________________________________
BIER mailing list
BIER@ietf.org
https://www.ietf.org/mailman/listinfo/bier