IETF Logo Mail Archive

Re: [mpls] 答复: draft-fang-mpls-label-forwarding-no-swap - how much does it really save?

Eric C Rosen <erosen@juniper.net> Fri, 24 July 2015 15:53 UTC

Return-Path: <erosen@juniper.net>
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 8F1661A1AE8 for <mpls@ietfa.amsl.com>; Fri, 24 Jul 2015 08:53:40 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.602
X-Spam-Level:
X-Spam-Status: No, score=-1.602 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, MIME_8BIT_HEADER=0.3, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] autolearn=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 Au0F3iuifhgc for <mpls@ietfa.amsl.com>; Fri, 24 Jul 2015 08:53:39 -0700 (PDT)
Received: from na01-bn1-obe.outbound.protection.outlook.com (mail-bn1bon0723.outbound.protection.outlook.com [IPv6:2a01:111:f400:fc10::1:723]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 8C7421A1A39 for <mpls@ietf.org>; Fri, 24 Jul 2015 08:53:39 -0700 (PDT)
Authentication-Results: juniper.net; dkim=none (message not signed) header.d=none;
Received: from [172.29.32.141] (66.129.241.14) by CY1PR0501MB1097.namprd05.prod.outlook.com (10.160.144.139) with Microsoft SMTP Server (TLS) id 15.1.219.17; Fri, 24 Jul 2015 15:53:34 +0000
To: Lizhenbin <lizhenbin@huawei.com>, "mpls@ietf.org" <mpls@ietf.org>, Andrew Qu <andrew.qu@mediatek.com>, Alexander Vainshtein <Alexander.Vainshtein@ecitele.com>, Shahram Davari <davari@broadcom.com>, Robert Raszuk <robert@raszuk.net>
References: <DB3PR03MB0780AE3E11BEA6B29B81FF5B9D810@DB3PR03MB0780.eurprd03.prod.outlook.com> <EA360A7AB9D90D4B9E9173B6D27C371EE3F60C0D@MTKMBS61N1.mediatek.inc> <5A5B4DE12C0DAC44AF501CD9A2B01A8D8CA1BFBE@nkgeml506-mbx.china.huawei.com>
From: Eric C Rosen <erosen@juniper.net>
Message-ID: <55B25F79.1000700@juniper.net>
Date: Fri, 24 Jul 2015 11:53:29 -0400
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0
MIME-Version: 1.0
In-Reply-To: <5A5B4DE12C0DAC44AF501CD9A2B01A8D8CA1BFBE@nkgeml506-mbx.china.huawei.com>
Content-Type: text/plain; charset="windows-1252"; format="flowed"
Content-Transfer-Encoding: 7bit
X-Originating-IP: [66.129.241.14]
X-ClientProxiedBy: BLUPR18CA0026.namprd18.prod.outlook.com (25.162.230.36) To CY1PR0501MB1097.namprd05.prod.outlook.com (25.160.144.139)
X-Microsoft-Exchange-Diagnostics: 1; CY1PR0501MB1097; 2:TmrDCmG4iQa7W3MCpxm36p48zJywlWLZPsRsMRFxxY/Vvw7QRJk2kzddXhTJaJ5I; 3:VILBjR7XSRtHX5CJR4wb46R3SR2Wciq+bEB/mJ/9sxD7XHHi3OCSkx7ZWHGKbZxlyw6uwaAwwJPZ0NDyVEB4cHwF6egVGejeTkGFbRXGWt5ozIQFav4KZMvWPubyLsWYhVO/TNiELxPffjy3UnYyYA==; 25:YkWYJS3XAwZ83KJemaLHihWLvb7Rv5XONF2QzMNrr+pFENqlq8T5lpIrZOa1XExi5JI2lSYA59L8b+EOhy2G47uALV0VxSuiTmcaO2oFn5hziARxViHdciqAgGT5SiAnsSZb4NuB04bvLTv+7KaPq3RGvQ7ln1m+qfOPZiMfSdSoLHC1bGb1M/Xz6niFq9ax2SPK8hsfSk0MYY/iSKbuCIJDPegqdnQqH33/UJ6AyqCloCtRLv6znvYjfKdD9ms3MV3t5BSvFuBx86qp0BVCxg==
X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:CY1PR0501MB1097;
X-Microsoft-Exchange-Diagnostics: 1; CY1PR0501MB1097; 20: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; 4:O+raErSphNHyUAuSn6gwoisce39Q5OEncFPRWyG5G2ro2qiQ1YlAZsF5X1jktydSUkjL0pDcAqb0ZLl3lbfYEL9ykZ+YpumsX5Y1Cf0Z5Uo7EuQbT7Q6b1s6/JyJnDsEts7b0bLHEkWWE7oywNf04caTo8Z5k1DjD/Dxcf0lbPIGX2XVF83mhOWdte14PXa1LS2u9zuIHE+enSiWcgPMUl+ogAPx3TTg2azKb5OLZy4VrBiy8HV3CHdIFDPeFwyfjatMZb0d9JsQfIBNECQj5V0C6a8TTy2fuH6abUTuaBE=
CY1PR0501MB1097: X-MS-Exchange-Organization-RulesExecuted
X-Microsoft-Antispam-PRVS: <CY1PR0501MB1097453813A6EB168B731AC1D4810@CY1PR0501MB1097.namprd05.prod.outlook.com>
X-Exchange-Antispam-Report-Test: UriScan:;
X-Exchange-Antispam-Report-CFA-Test: BCL:0; PCL:0; RULEID:(601004)(5005006)(3002001); SRVR:CY1PR0501MB1097; BCL:0; PCL:0; RULEID:; SRVR:CY1PR0501MB1097;
X-Forefront-PRVS: 0647963F84
X-Forefront-Antispam-Report: SFV:NSPM; SFS:(10019020)(6009001)(6049001)(377454003)(479174004)(24454002)(47776003)(50466002)(86362001)(4001350100001)(46102003)(224303003)(122386002)(5001770100001)(230783001)(189998001)(87976001)(107886002)(33656002)(5001960100002)(42186005)(66066001)(83506001)(87266999)(80316001)(54356999)(65806001)(40100003)(36756003)(77096005)(76176999)(50986999)(23746002)(65956001)(64126003)(77156002)(2501003)(65816999)(2950100001)(92566002)(62966003)(4001430100001); DIR:OUT; SFP:1102; SCL:1; SRVR:CY1PR0501MB1097; H:[172.29.32.141]; FPR:; SPF:None; MLV:sfv; LANG:en;
X-Microsoft-Exchange-Diagnostics: 1; CY1PR0501MB1097; 23: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
X-Microsoft-Exchange-Diagnostics: 1; CY1PR0501MB1097; 5:Z7Nyb7f2XDwv6AEF2c1jySy+OmjbvA6ggJRGPZ8yjdhZIN61YKCuPXAgJmL44JmvLdmvTSVMdESmFdLkGMgULhNjiPBffOAkHImMugEX0qNNDysBzrK0+OXIH3P5xJzR234XwxHhVzaJ9o5Fy/1jeg==; 24:pka0TBjgjGb46bDjfcvGs3B9hF7obbthWllPvI84oR/7FeKfe9qyFB4VT+P0ywSVnHmxDwQyFnCe2uOn+QJo3pFK9+Fw0Kds1YDIgEXcqV8=; 20:+ROlq2IuHWmeLV/r4RbkqbJFzaTzYqB9ZXOOT5VHwa8iKj6Od/ESmLR9WmBvMw7yajpPcjSgOYD4mozzxdSO0w==
X-OriginatorOrg: juniper.net
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 24 Jul 2015 15:53:34.7719 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY1PR0501MB1097
Archived-At: <http://mailarchive.ietf.org/arch/msg/mpls/gPewBSkMgzGDgBdgd7e2k3i7aCE>
Subject: Re: [mpls] 答复: draft-fang-mpls-label-forwarding-no-swap - how much does it really save?
X-BeenThere: mpls@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Multi-Protocol Label Switching WG <mpls.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/mpls>, <mailto:mpls-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/mpls/>
List-Post: <mailto:mpls@ietf.org>
List-Help: <mailto:mpls-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/mpls>, <mailto:mpls-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 24 Jul 2015 15:53:40 -0000

On 7/24/2015 4:40 AM, Lizhenbin wrote:
> In fact, according to implementation, the SWAP can be seen as POP a
> label, then PUSH a label.

Certainly the architecture could have been written this way.  But it 
wasn't ;-)  It was written in such a way as to emphasize the difference 
between operations that change the size of the label stack and 
operations that do not.

These concepts do not necessarily show up at all in the forwarding 
logic.  All the forwarding plane has to know is what the rewrite string 
is, where to put it, and how to adjust any TTL and/or checksum fields 
that might be in it.

v2.26.15 | Report a Bug | By Email | System Status