Re: [pim] pim wg adoption call for draft-chen-pim-srv6-p2mp-path-01

Huaimo Chen <huaimo.chen@futurewei.com> Fri, 22 January 2021 22:21 UTC

Return-Path: <huaimo.chen@futurewei.com>
X-Original-To: pim@ietfa.amsl.com
Delivered-To: pim@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 3DDA03A0CF5 for <pim@ietfa.amsl.com>; Fri, 22 Jan 2021 14:21:06 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.089
X-Spam-Level:
X-Spam-Status: No, score=-2.089 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HTML_MESSAGE=0.001, RCVD_IN_MSPIKE_H2=-0.001, T_SPF_PERMERROR=0.01, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=futurewei.com
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 0FAUcyzPbTV9 for <pim@ietfa.amsl.com>; Fri, 22 Jan 2021 14:21:04 -0800 (PST)
Received: from NAM12-BN8-obe.outbound.protection.outlook.com (mail-bn8nam12on2092.outbound.protection.outlook.com [40.107.237.92]) (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 0C2C83A0CF2 for <pim@ietf.org>; Fri, 22 Jan 2021 14:21:03 -0800 (PST)
ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=mVTbIZTnAeMrqz88QlTVV93UO0BjVDVCVl/TgG1Ap6YZcpBoKaX6ubmxnT6E5x0PHPgVVXKSiFQaI/HIqM4Wc/5PIb7E2D1OvhMIS3clWIppmj/ZMoemfmj4BDpKryszaoJ/Kcq/j2os+rXVpo6TcrGjBY49BgAMolf+KTwQB/hiYG3NpQb5OZYXXH8wDzGkzvS/I9wn0UAtHlCgl1WZltCy8Vwxhoe6R9x2mxifvka9LJaQ1ocP8WoTyYcG/5aIt4+WgZE4PGd7HmOiGeR3p+58P90RD3vRAlzGWMxoV+Et1ljVEP1xJZBs8PR33VXBSw/p+tI+i7Hs0plj1/AVCA==
ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=20P3NJ5vQin6FK8rohLrVC+m8iMp6K1RqI+TREU+63c=; b=nJ/sfB9cjHfaTANxAoF638+zUKv3CLamVh/y2RT7kStHG7p9qmlSqcDr79Hn9Vzk9wGb7E9Hxrzc9PWT7U98WZJ5l0o/x/ge6jC4gjOt0462qLNpuwQxRBv3dUUq9S8vOfDFGpJwY6RJM42vYUYtc0iCvM7X4iQp9+jzAGEFM9mr0W3fkPlnzIb++y/dNDhbyeiJE4OcMKvtGThkTO6dG7vhV6936zEpWZWo0xCaHsoulYBuf+O7dHXS4Qp0ri+s4z2+k7U7qTojIyjQHOF3KncCy5lyB3+cmHNNr3qOx7833CCe5wTHcHRqpjxdc9T5h5PRXA6FCkjbcwIJU0iENA==
ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=futurewei.com; dmarc=pass action=none header.from=futurewei.com; dkim=pass header.d=futurewei.com; arc=none
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Futurewei.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=20P3NJ5vQin6FK8rohLrVC+m8iMp6K1RqI+TREU+63c=; b=IlcRxeR+gsEnN2HdzmvOUdWFwHy6eR3zS+IaukgO2rfOFNKeOXWE8iGuchO3+dpYMceoG93QhpdZwJ9Ap/a3+GWqUg0bxhuPjhKaMaHtezm7eJtr0ZWitFLFtpmFRFuQCLmh5cOA/JTNPcqmoB2g7OkgXMf0s4RzkofqmNgG7ag=
Received: from (2603:10b6:208:263::16) by MN2PR13MB3758.namprd13.prod.outlook.com (2603:10b6:208:1e3::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3805.6; Fri, 22 Jan 2021 22:21:01 +0000
Received: from MN2PR13MB4087.namprd13.prod.outlook.com ([fe80::14ed:3768:8b86:be32]) by MN2PR13MB4087.namprd13.prod.outlook.com ([fe80::14ed:3768:8b86:be32%8]) with mapi id 15.20.3805.009; Fri, 22 Jan 2021 22:21:01 +0000
From: Huaimo Chen <huaimo.chen@futurewei.com>
To: "Acee Lindem (acee)" <acee=40cisco.com@dmarc.ietf.org>, Rishabh Parekh <rishabhp@gmail.com>, Stig Venaas <stig@venaas.com>
CC: "pim@ietf.org" <pim@ietf.org>
Thread-Topic: [pim] pim wg adoption call for draft-chen-pim-srv6-p2mp-path-01
Thread-Index: AQHW6FOGkwIZIOil2EGxf1caMC/sV6ovinwAgAK9o4CAAf7o6Q==
Date: Fri, 22 Jan 2021 22:21:01 +0000
Message-ID: <MN2PR13MB4087B66547A6587E6F32F3F0F2A09@MN2PR13MB4087.namprd13.prod.outlook.com>
References: <CAHANBtLs2F+x9ny8Jv=qe-28dFubcQL=k8bYXO4sybBr_Zpe5Q@mail.gmail.com> <CABjMoXZL9PphjcjT+MwSVPOMNPO320f7bvYGGG1U2V56ypP_nA@mail.gmail.com>, <21FFA649-7919-419B-B591-232891E68260@cisco.com>
In-Reply-To: <21FFA649-7919-419B-B591-232891E68260@cisco.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
authentication-results: dmarc.ietf.org; dkim=none (message not signed) header.d=none;dmarc.ietf.org; dmarc=none action=none header.from=futurewei.com;
x-originating-ip: [2601:199:4300:8e5a:7127:b391:f087:26b1]
x-ms-publictraffictype: Email
x-ms-office365-filtering-correlation-id: fcf424ec-6e7e-416a-039b-08d8bf23ffea
x-ms-traffictypediagnostic: MN2PR13MB3758:
x-microsoft-antispam-prvs: <MN2PR13MB375843AE44EE4ABF13D3DFF1F2A09@MN2PR13MB3758.namprd13.prod.outlook.com>
x-ms-oob-tlc-oobclassifiers: OLM:10000;
x-ms-exchange-senderadcheck: 1
x-microsoft-antispam: BCL:0;
x-microsoft-antispam-message-info: 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
x-forefront-antispam-report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:MN2PR13MB4087.namprd13.prod.outlook.com; PTR:; CAT:NONE; SFS:(4636009)(39840400004)(396003)(376002)(136003)(366004)(346002)(86362001)(55016002)(8676002)(186003)(316002)(71200400001)(2906002)(6506007)(33656002)(4326008)(66946007)(8936002)(66446008)(478600001)(64756008)(66556008)(66476007)(76116006)(44832011)(52536014)(9686003)(5660300002)(83380400001)(19627405001)(110136005)(7696005); DIR:OUT; SFP:1102;
x-ms-exchange-antispam-messagedata: =?Windows-1252?Q?qpx9Psssijowz9Rw9sgV0sfdD/r+2xx1zHGnyGEO1BKnKunIyA99Bz8c?= =?Windows-1252?Q?lBC2WVdc7f58iRaOaVA4KvEp7/cWtyyPZmQgO/UY2XnsTyUGrTqIq636?= =?Windows-1252?Q?gfuSkFypmLbWNFP78jRNdTram7HMlRYi5dBfHnaOaeNQkZ2bMj7fh1Vd?= =?Windows-1252?Q?51YIHihGHhtqdLXHiJGH3EYDlp1r1TGWkiWnGJaskJpaveJ1UoM3Ns9O?= =?Windows-1252?Q?6vLr1iml+ZhTaCgK5zbA++++/FuxCaQNONlcqYre4imG4WsZU/fVqP5O?= =?Windows-1252?Q?27WHCV1d+lwrMgiVhygXanEezu13kD0xYPnoeYueQi+cv/Yw9EB3DgT3?= =?Windows-1252?Q?xQ8juhnm7j0CHX2V4PXtMf6CN+I0e0ZxaKW8cNYS+05fBXEHkApaBXhs?= =?Windows-1252?Q?G26b830lIpiujkRQ8Ns/YDhjRKIygVt+Mqg5NKMzMYsgDNel80i4ZioL?= =?Windows-1252?Q?U35hyam+dqmqJtAFhRjfV0c8W/eh8XdkmlbQTd35bGgW6cawa3wAaNSn?= =?Windows-1252?Q?Sg3pSLrgeastCwBDKRVzKXvPxqr7DfQx+cxAtstSESaVMiz5ZlrDTDJA?= =?Windows-1252?Q?4fo1vHH/tfzVX0N6CIVdiGPjTx4H0wd7rgtd8zJltTBX2kW1GlU9iYQ0?= =?Windows-1252?Q?yw+JmaxxwgB4SZKyl/qHfEJ7u9IWcnB1IpYnI1yiSNBCfN8hBgcPjrjB?= =?Windows-1252?Q?ISgApESEWD4zCLir4ukeRzzyjmyscWRm5jeY/nVHJ2hv2vwhsbktcrCg?= =?Windows-1252?Q?4am563tj12vbvus8YhOwbsnEcYq/MacR4yMem1aQKU+O+2jkNHMubiL9?= =?Windows-1252?Q?9ieI1QNJrfsW7V5N+EeHeCnFnrX2zGiTqR9FZmMBp31JkL87yGpeqd0e?= =?Windows-1252?Q?9O5RVjrKQQUZRs55bpcUDn6mj3XsdQSXuzTDs3dfZyCuQxMeidTotUe4?= =?Windows-1252?Q?UudK1SwMvgL4x3C3YXpuPOP0PWaLJEudUBTr1TbLG2c/yq9YInIk4xM8?= =?Windows-1252?Q?1rYos7LnTqDoeVYcsgRhObRJThDOwZtQ1TPGrPBUCDl19sdcBrqC7sM4?= =?Windows-1252?Q?JmQz1PbaNaROFNbpFGl/jGedX7hN/qYI7REL6wX02enwAuG3RLQZ1dxb?= =?Windows-1252?Q?g8aFBVJSRVIfVJ8sP/aAykwwR/1YPok3XVxYBBTE37Gi/4Vqs/aeyzFl?= =?Windows-1252?Q?vJvRbJqhFrC8pjivgb2LB0sz7Z9zZnbR?=
x-ms-exchange-transport-forked: True
Content-Type: multipart/alternative; boundary="_000_MN2PR13MB4087B66547A6587E6F32F3F0F2A09MN2PR13MB4087namp_"
MIME-Version: 1.0
X-OriginatorOrg: Futurewei.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: MN2PR13MB4087.namprd13.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: fcf424ec-6e7e-416a-039b-08d8bf23ffea
X-MS-Exchange-CrossTenant-originalarrivaltime: 22 Jan 2021 22:21:01.0445 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 0fee8ff2-a3b2-4018-9c75-3a1d5591fedc
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: CKSBttc3A+SL+u3R6aN7/aQuwskebQTdtT5uSgWGffIGjazhgWn1PuQzvuRCQwmeAi5XP9A8Yc+F1Lx3WWWCFA==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN2PR13MB3758
Archived-At: <https://mailarchive.ietf.org/arch/msg/pim/vGZ6tcfpUQdcml2VP266mHMr2cY>
Subject: Re: [pim] pim wg adoption call for draft-chen-pim-srv6-p2mp-path-01
X-BeenThere: pim@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Protocol Independent Multicast <pim.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/pim>, <mailto:pim-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/pim/>
List-Post: <mailto:pim@ietf.org>
List-Help: <mailto:pim-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/pim>, <mailto:pim-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 22 Jan 2021 22:21:06 -0000

Hi Acee,

    Thank you very much for your comments.
    My responses are inline below with prefix [HC].

Best Regards,
Huaimo

I think the concept of the ingress node encoding the complete MDT in the segment
list is flawed and won’t scale. At some point, the segment list is finite.
[HC]: In Segment Rouging (SR), for an explicit point-to-point (P2P) path/tunnel
from an ingress to an egress,  the ingress node encodes the path in the segment
list. This should improve the network scalability since there is no per-path state
in the core of the network.
For an explicit point-to-multipoint (P2MP) path/tree (or say MDT),
it seems natural for the ingress node of the P2MP path to encode the P2MP path
in the segment list. This should also improve the network scalability since
there is no per-P2MP-path (or say per-MDT-tree) state in the core of the network.
For a P2MP path/tree, its ingress node does not have to encode the complete
MDT in the segment list. If the tree has a few separated sub-trees from the ingress,
for each of these sub-trees, the ingress node encodes it in a separated
segment list and sends the multicast packet with the segment list for the
sub-tree to the next hop node along the link on the sub-tree.
Regarding to the finite size of the segment list, for a P2MP path/tree,
the tree can be "split" into multiple sub-trees such that each of the sub-trees
can be encoded in the segment list of the finite size.

Additionally, the network programming is fairly complex.
[HC]: The document on the network programming is on its way to be a RFC after WGLC.
With the network programming, a function may be defined by a program/procedure
for a SID or a set of SIDs. It seems easy to add a new function in this way.

Finally, a separate multicast SID must be provisioned and advertised for every
multicast egress or replication node. Please let me know if I’m missing something.
[HC]: A separate multicast SID must be provisioned for every replication node
and a central controller such as PCE knows the SID on the node.
It seems that this is similar to a replication SID for every replication node.
We will update the draft with some details accordingly to address your concerns.


I don’t support WG adoption. For those supporting adoption, I’d ask if you plan to actually implement this.

Thanks,
Acee