Return-Path: X-Original-To: mpls@ietfa.amsl.com Delivered-To: mpls@ietfa.amsl.com Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 902491A87B1; Tue, 17 Mar 2015 10:15:39 -0700 (PDT) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -4.201 X-Spam-Level: X-Spam-Status: No, score=-4.201 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, SPF_PASS=-0.001] autolearn=ham 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 AJxE2RlsQV0N; Tue, 17 Mar 2015 10:15:38 -0700 (PDT) Received: from usevmg21.ericsson.net (usevmg21.ericsson.net [198.24.6.65]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 094BA1A87AF; Tue, 17 Mar 2015 10:15:37 -0700 (PDT) X-AuditID: c6180641-f790b6d000004359-2e-5507ffaa13a8 Received: from EUSAAHC005.ericsson.se (Unknown_Domain [147.117.188.87]) by usevmg21.ericsson.net (Symantec Mail Security) with SMTP id AE.2E.17241.AAFF7055; Tue, 17 Mar 2015 11:19:22 +0100 (CET) Received: from EUSAAMB103.ericsson.se ([147.117.188.120]) by EUSAAHC005.ericsson.se ([147.117.188.87]) with mapi id 14.03.0210.002; Tue, 17 Mar 2015 13:15:31 -0400 From: Antoni Przygienda To: Xuxiaohu , "stbryant@cisco.com" , Eric C Rosen , BIER Thread-Topic: [Bier] Encapsulation first nibble Thread-Index: AQHQXcZr1RiePFKtRU2KrQ7DzVhUo50bFkcAgAWxRoCAAAe/AIAAHlkA Date: Tue, 17 Mar 2015 17:15:31 +0000 Message-ID: <2E4BB27CAB87BF43B4207C0E55860F1827D3C5@eusaamb103.ericsson.se> References: <55033E87.3030305@juniper.net> <5503403E.4050304@cisco.com> <1FEE3F8F5CCDE64C9A8E8F4AD27C19EE0831CB77@NKGEML512-MBS.china.huawei.com> <1FEE3F8F5CCDE64C9A8E8F4AD27C19EE0831CBB2@NKGEML512-MBS.china.huawei.com> In-Reply-To: <1FEE3F8F5CCDE64C9A8E8F4AD27C19EE0831CBB2@NKGEML512-MBS.china.huawei.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [147.117.188.9] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrPLMWRmVeSWpSXmKPExsUyuXRPuO6q/+yhBtdPKFgsnbGHyWLdhg/M FreWrmS1ePJgK7vFuadzGC22nl/F6MDmMeX3RlaPliNvWT2WLPnJ5HG96Sp7AEsUl01Kak5m WWqRvl0CV8aOlZtZCzazVZzu2cvawNjB2sXIySEhYCKx5dxBJghbTOLCvfVsXYxcHEICRxgl Li2fzArhLGeUOHv/KVgVm4CFxOVvT5lBEiICHYwSSxZsAhvFLOAk0bD8MiOILSygJ3F+y2M2 EFtEQF9i+flrQDUcQLabxMmXASBhFgFVidkXn4O18gp4S5y8eY8FxBYSuM8o8e2NCojNKRAm cW3KPbC9jEDXfT+1hglilbjErSfzoa4WkFiy5zwzhC0q8fLxP6jPFCX29U9nh6jXkViw+xMb hK0tsWzha2aIvYISJ2c+YZnAKDYLydhZSFpmIWmZhaRlASPLKkaO0uLUstx0I8NNjMAYOybB 5riDccEny0OMAhyMSjy8BhrsoUKsiWXFlbmHGKU5WJTEecuuHAwREkhPLEnNTk0tSC2KLyrN SS0+xMjEwSnVwNh+/u+dSJcnBqp7Ug1Pp+zsV2tPyxZjYNm+c1nir5llJ331NJL6mbcyvYlp 22VuPX9u4obZJbqG4X45tqzPnZOMa1hz0n5dzPk7Vfl8gLHtnidMc986hCqLZTEfEBA4N0Xi 27Zl+bpJLOuPbEkKjj/U9Hpiy80T9/R6m+IPved0LO3blPSnXYmlOCPRUIu5qDgRAEt35GqS AgAA Archived-At: Cc: "mpls@ietf.org" , "sfc@ietf.org" Subject: Re: [mpls] [Bier] Encapsulation first nibble X-BeenThere: mpls@ietf.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Multi-Protocol Label Switching WG List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Mar 2015 17:15:39 -0000 Not being much of an encapsulation, data plane guy myself, I wonder a tad h= ow hacky those 'heuristics' are. Last label indicates clearly a BIER heade= r is following. For the LSRs that do not support BIER and do not parse the = BIER encaps there is no reason to look 'behind the label'. Multiple sub-do= mains allow for clean separation of traffic with different properties if ne= eded and with that there is even less reason for some kind of 'heuristic' D= PI Now, given some 'heuristics' are in place no matter what value we put into = the nibble, sooner or later we'll collide with it no matter what value we p= ick since such 'heuristics' basically try to parse bits without understandi= ng their context and with that can easily mistake an 'eye' for an 'I' or an= 'aye'.=20 --- tony=20