Re: [spring] draft-ietf-spring-srv6-network-programming - Extraneous functions

"Wang, Weibin (NSB - CN/Shanghai)" <> Fri, 13 December 2019 14:21 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 5984F120856 for <>; Fri, 13 Dec 2019 06:21:03 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.898
X-Spam-Status: No, score=-1.898 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, HTML_MESSAGE=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id 2MTnsWvrWxXN for <>; Fri, 13 Dec 2019 06:21:00 -0800 (PST)
Received: from ( []) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id B27FC120854 for <>; Fri, 13 Dec 2019 06:20:59 -0800 (PST)
X-AuditID: ac18929d-551ff70000002afa-d3-5df39e46b1d4
Received: from (Unknown_Domain []) (using TLS with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) by (Symantec Messaging Gateway) with SMTP id 93.56.11002.64E93FD5; Fri, 13 Dec 2019 22:20:54 +0800 (HKT)
Received: from ( by ( with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Fri, 13 Dec 2019 22:20:53 +0800
Received: from ([]) by ([]) with mapi id 15.01.1713.007; Fri, 13 Dec 2019 22:20:53 +0800
From: "Wang, Weibin (NSB - CN/Shanghai)" <>
To: Ron Bonica <>, "" <>
Thread-Topic: draft-ietf-spring-srv6-network-programming - Extraneous functions
Thread-Index: AdWxJISO1DZtWCKVSoaJRshbG+5IZgAI9pFAABvmz4A=
Date: Fri, 13 Dec 2019 14:20:53 +0000
Message-ID: <>
References: <> <>
In-Reply-To: <>
Accept-Language: en-US
Content-Language: en-US
msip_labels: MSIP_Label_0633b888-ae0d-4341-a75f-06e04137d755_Enabled=True; MSIP_Label_0633b888-ae0d-4341-a75f-06e04137d755_SiteId=bea78b3c-4cdb-4130-854a-1d193232e5f4;; MSIP_Label_0633b888-ae0d-4341-a75f-06e04137d755_SetDate=2019-12-12T19:56:06.0371162Z; MSIP_Label_0633b888-ae0d-4341-a75f-06e04137d755_Name=Juniper Business Use Only; MSIP_Label_0633b888-ae0d-4341-a75f-06e04137d755_Application=Microsoft Azure Information Protection; MSIP_Label_0633b888-ae0d-4341-a75f-06e04137d755_ActionId=acf320b4-d8b2-4a52-a650-e570b8c496c0; MSIP_Label_0633b888-ae0d-4341-a75f-06e04137d755_Extended_MSFT_Method=Automatic
x-originating-ip: []
Content-Type: multipart/alternative; boundary="_000_2574285d812c45d6a92618e3e63826c9nokiasbellcom_"
MIME-Version: 1.0
X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrJIsWRmVeSWpSXmKPExsXS/ts4Q9dt3udYg2/HeCxa915jtDh+4Tej A5PHiWVXWD2WLPnJFMAUxWWTkpqTWZZapG+XwJWxves3e8GUFsaK74/NGxgflHcxcnJICJhI fLl0m6WLkYtDSOAQk8S6P8cZIZy/jBLHt0xmh3A2MUpMb93GBtLCJuAmMWnbLjBbRCBGYuPW 6WC2sICfxKxNN9gh4oES5099g6qxkuj8c5QJxGYRUJX4eraZEcTmFbCTOHfyFBPEgomMEid2 /2YFSXAK2Ets39nNDGIzCohJfD+1BqyZWUBc4taT+UwQdwtILNlznhnCFpV4+fgfK8ggXoFd rBKPX84FcjiAEkoSfRugelMl+lf2skEsFpQ4OfMJywRG0VlIxs5CUjYLSRlEXEtiXsNvqBpF iSndD9khbE2JK5MPQdnaEssWvmZewMi+ilE6Oa84I6s4NzPPwFQvLz87M1G3OCk1J0cvOT93 EyMwAtdITJq7g7GzM/4QowAHoxIPL0PKp1gh1sSy4srcQ4wSHMxKIryp2p9jhXhTEiurUovy 44tKc1KLDzFKc7AoifO2TF4YKySQnliSmp2aWpBaBJNl4uCUamDM1P3obeDR4msxfVeq77rU lx/rNwmxcKgvC9uUsbl8S7hEmVxeQ/3RdSeM33h3srw/FrdSfCvnk+RL9vnzJy0Qt5z4vvVY 2Ks15QXRn+ZsW7by07WECiMxZm3xpc1b/tx/uMHN8vGBwuzC8z2XGOtmurYyGL4J896y3mVm 2ofEe0dZV89Xm6usxFKckWioxVxUnAgADWWoZ7wCAAA=
Archived-At: <>
Subject: Re: [spring] draft-ietf-spring-srv6-network-programming - Extraneous functions
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Source Packet Routing in NetworkinG \(SPRING\)" <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Fri, 13 Dec 2019 14:21:03 -0000

Hi Authors:

I look at the following SIDs function again, and I indeed fail to find useful meaning of the combination of USP & USD, as well as {PSP & USP & USD}.
Given that there are no 2 or more successive SRH instances in one packet in this draft, So Regardless of which specific packet whose SRH instance include the same SID below in last location, the final behavior of these SIDs in different packet¡¯s SRHs are always the same, either USP or USD, it is up to the execution order among the USD and USP, because these SIDs are executed in last node of segment list and their pre-condition is same, i.e ¡° if {segment left ==0}¡± in same location in Pseudocode module.
Do you give a use case to explain for them, for example, the one SID below of one SRH instance has behavior for USP, at the same time, the same SID of another SRH instance of another packet has behavior for USD.

0x001E |  End with USP&USD
0x0022 |  End.X with USP&USD
0x0026 |  End.T with USP&USD


Wang Weibin

From: Wang, Weibin (NSB - CN/Shanghai)
Sent: 2019Äê12ÔÂ13ÈÕ 8:06
To: 'Ron Bonica' <>rg>;
Subject: RE: draft-ietf-spring-srv6-network-programming - Extraneous functions

Hi Ron,

I think the same SID£¬such as you mention, May be included in different SRH of different packets, so the same SID have different behavior in different packet whose SRH include it.


Wang Weibin

From: spring <<>> On Behalf Of Ron Bonica
Sent: 2019Äê12ÔÂ13ÈÕ 3:56
Subject: [spring] draft-ietf-spring-srv6-network-programming - Extraneous functions


Are there use cases for the following functions:

  *   0x001F ¨C END with PSP, USP and USD
  *   0x0023 ¨C END.X with PSP, USP and USD
  *   0x0027 - END.X with PSP, USP and USD

It seems that if the SRH was removed at the penultimate segment, there is little sense in removing it again at the ultimate segment.


Juniper Business Use Only