Re: [Detnet] Packet Ordering Function (draft-varga-detnet-pof-00.txt)

Stephan Kehrer <Stephan.Kehrer@belden.com> Mon, 26 April 2021 09:25 UTC

Return-Path: <Stephan.Kehrer@belden.com>
X-Original-To: detnet@ietfa.amsl.com
Delivered-To: detnet@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 179F03A15AA for <detnet@ietfa.amsl.com>; Mon, 26 Apr 2021 02:25:42 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.509
X-Spam-Level:
X-Spam-Status: No, score=-1.509 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, HTTPS_HTTP_MISMATCH=0.1, RCVD_IN_MSPIKE_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_PASS=-0.001, T_KAM_HTML_FONT_INVALID=0.01, URIBL_BLOCKED=0.001, URI_NOVOWEL=0.5] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=belden.com header.b=q6lgc5Yg; dkim=fail (1024-bit key) reason="fail (message has been altered)" header.d=beldeninc.onmicrosoft.com header.b=n0kKWn5T
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 ENuAQ5wBJpxG for <detnet@ietfa.amsl.com>; Mon, 26 Apr 2021 02:25:37 -0700 (PDT)
Received: from mail3.belden.com (mail3.belden.com [12.168.192.246]) (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 CB24F3A15A8 for <detnet@ietf.org>; Mon, 26 Apr 2021 02:25:36 -0700 (PDT)
Received: from pps.filterd (dcric1ppa03pa.mcp.local [127.0.0.1]) by dcric1ppa03pa.mcp.local (8.16.0.43/8.16.0.43) with SMTP id 13Q96fHc013434; Mon, 26 Apr 2021 05:25:32 -0400
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=belden.com; h=from : to : cc : date : message-id : references : in-reply-to : content-type : mime-version : subject; s=beldenpps; bh=OCovHvwO4jERQH3t9ISmWYZkj8Kms646eeBjqoRINoQ=; b=q6lgc5YgivRKU2MEi2wNSbuHY5jGAhYFx023+V8+qXn4InyEYnDymrKWH6pq9na4GF+G nwVGZkWOzKoDf9RvXTuISkQebTNxgHssecazYe2VNUwLJ7EGjY1arqNv5Nfu6iJ0giYS Um0pdB+uVEi7pdDlu9qer3LR8kvmYpsZGE0=
Received: from dcric1exc04pa.mcp.local (dcric1exc04pa.mcp.local [10.10.181.24]) by dcric1ppa03pa.mcp.local with ESMTP id 385pmsrkb0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=FAIL); Mon, 26 Apr 2021 05:25:31 -0400
Received: from DCRIC1EXC01PA.mcp.local (10.10.181.21) by DCRIC1EXC04PA.mcp.local (10.10.181.24) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 26 Apr 2021 05:25:31 -0400
Received: from NAM12-MW2-obe.outbound.protection.outlook.com (104.47.66.46) by DCRIC1EXC01PA.mcp.local (10.10.181.21) with Microsoft SMTP Server (TLS) id 15.0.1497.2 via Frontend Transport; Mon, 26 Apr 2021 05:25:30 -0400
ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=PJUxDw8LDyy/q/5+myrnhMKro+ZYFkKSotzs6s0fb6AdEcD09UBQCViW4qcN90J6UVJkgK/lBwHKzkVIhuHHt2ugU1hlazQH0mxO2vJWO8R9kOJLH7TM5nFJKM5A7vYQvJJAbLR+O4iBb8MQfs0s+WFd1KFm/GZGTWeYBiyd8bsMoiuoDuPi8z2jhhct17fZullp65UpCdpYqHXsAkjzRuG2Baa0VT8VjSiW6TazgPMnU6MCFt/+Dvg/SyqQPjTFtzodMLDj+z0uuR5tXkdzqnh+9oA+gqnT3OIQwIrfpgHMZjTltjIZtxRS9QCqJpY9twvnc4WVrcMeP2LbBkIjaQ==
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=H4vIfVL5u1lZWFyOgxITNfWaws08jL6nuASEtE0J9A8=; b=Whk3BjA+Z9EjkhiYTy9JpadyWaxmeMxGD6hzu7TZrpQxGibroJRC8bxxbY85rqclA3POhUgsfjmeRuz1fxwW/PHwhXyzJlkax7H+keVgTIQr+CteaaElrg2Axjf0kQkNB7aFf6x8Fk02BcM/azU0VLi80ca9AOKkf1GiWzwXsVVB90hIOE7kAyaQmsos8A8WblL/JwmqPotYKT8K3xfLqbEbY7qDvytgT4xmJaNiua9rRP0dHll7KU/tdTPpJXUcNH2N1w0kfnh9Dusww19bF2D09EpI38tKN1/pvRhHGzm2bKV5lSI4DdZVhy+bmX1F2d6X2BCm7Azk2iFkTpgQdQ==
ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=belden.com; dmarc=pass action=none header.from=belden.com; dkim=pass header.d=belden.com; arc=none
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=beldeninc.onmicrosoft.com; s=selector1-beldeninc-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=H4vIfVL5u1lZWFyOgxITNfWaws08jL6nuASEtE0J9A8=; b=n0kKWn5T0iTOM8TVT8Jp4rXxhaxkG8ow6ya6HJlf0WRefywIaYWQ/5aY/wfNftWJ4h/ARMUYMA9JxQGsv+7bQ7z/34foSrOXARF5Iwi7jByt8tLQsoF9lYds23lkpO1k6fd5XnneGKWf1Js1Pxd13ot5WJLGk6GF5vS0QdXkZw8=
Received: from MWHPR18MB1053.namprd18.prod.outlook.com (2603:10b6:300:a4::15) by MW3PR18MB3577.namprd18.prod.outlook.com (2603:10b6:303:5e::13) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4065.20; Mon, 26 Apr 2021 09:25:27 +0000
Received: from MWHPR18MB1053.namprd18.prod.outlook.com ([fe80::50c7:1cea:ff75:124c]) by MWHPR18MB1053.namprd18.prod.outlook.com ([fe80::50c7:1cea:ff75:124c%3]) with mapi id 15.20.4065.027; Mon, 26 Apr 2021 09:25:27 +0000
From: Stephan Kehrer <Stephan.Kehrer@belden.com>
To: Greg Mirsky <gregimirsky@gmail.com>
CC: "detnet@ietf.org" <detnet@ietf.org>
Thread-Topic: [EXTERNAL] Re: [Detnet] Packet Ordering Function (draft-varga-detnet-pof-00.txt)
Thread-Index: Adc1p0Koa3Cy4+26RzSR8F6P/oLW6gC/m5IAAHWKa7A=
Date: Mon, 26 Apr 2021 09:25:26 +0000
Message-ID: <MWHPR18MB10533260740A2FF65559CBC4E9429@MWHPR18MB1053.namprd18.prod.outlook.com>
References: <AM0PR0702MB360326E7D3B09FC8FF4E44CEAC489@AM0PR0702MB3603.eurprd07.prod.outlook.com> <CA+RyBmXOKoYpiR1TT=FWKYFwW5eHN0BbWOQOkxWc8tQnKYwVSw@mail.gmail.com>
In-Reply-To: <CA+RyBmXOKoYpiR1TT=FWKYFwW5eHN0BbWOQOkxWc8tQnKYwVSw@mail.gmail.com>
Accept-Language: en-US
Content-Language: de-DE
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
authentication-results: gmail.com; dkim=none (message not signed) header.d=none;gmail.com; dmarc=none action=none header.from=belden.com;
x-originating-ip: [46.5.211.155]
x-ms-publictraffictype: Email
x-ms-office365-filtering-correlation-id: d4d89b1d-bab1-44d5-2cb5-08d908953a45
x-ms-traffictypediagnostic: MW3PR18MB3577:
x-microsoft-antispam-prvs: <MW3PR18MB35772A42AED759D8AB68C2E8E9429@MW3PR18MB3577.namprd18.prod.outlook.com>
x-ms-oob-tlc-oobclassifiers: OLM:8882;
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:MWHPR18MB1053.namprd18.prod.outlook.com; PTR:; CAT:NONE; SFS:(366004)(136003)(346002)(376002)(396003)(39840400004)(6506007)(53546011)(83380400001)(71200400001)(478600001)(6916009)(5660300002)(9686003)(76116006)(8936002)(19627235002)(966005)(66556008)(66446008)(86362001)(64756008)(166002)(7696005)(52536014)(66574015)(4326008)(66946007)(66476007)(8676002)(2906002)(316002)(122000001)(38100700002)(55016002)(33656002)(26005)(186003); DIR:OUT; SFP:1101;
x-ms-exchange-antispam-messagedata: =?utf-8?B?RzZVakdxT1owS0VYd3hzSkJjOTM2WFVEY280d2xnN2xVTXF0VFc5dHdWT0VW?= =?utf-8?B?Yk1QWGZDdnUveUdFUEV4VE9FWkZpcHoxa3BXUjdYUzRTc2xLTGpVWWp0T0t4?= =?utf-8?B?Z0h2Zk5sUGlqK2ZvaGdmQjgvMllaekV6YWI4L0lmUUVMSlpjaG04VnFKSER5?= =?utf-8?B?eUxZWVFkbGRuNFR4V1ZjdzUzZkl4N2k3YmVjc0wrMk1seHVBNDUyU2t0OWE2?= =?utf-8?B?QitJSjB4R3dlYm9rOTRLN1NESkJpYnJseENVNWQ5bUgwb0cwSGJJWi9wK015?= =?utf-8?B?TkVMSXNFeEJmTjFrNjdCYzMrNmtUbG4zTWVHQ0NzbDRGMXdLY3Z1aG5MUmdu?= =?utf-8?B?WHRPVHZhN3BHT1lINkhUTXJncU92d0NrQ1hyNGwzZm9xK0pIZ1NpeWhRbEtW?= =?utf-8?B?SG1EWTMzQ2tvWGVBZWdObXNmMFppaFNhL2FIQ0hGMnBFRU16WnF3cHZlMkdj?= =?utf-8?B?VjdkYmR5WUhFMTM4blFYMXVoTnJ4YmxlZHJXeUViMGhQc2U3RlBjaGdwMVor?= =?utf-8?B?a0xRNU5sTjd3MkJOaktETnk3WjFndzBydmZRUWhRcFJlbkZJWHYrSW54VnRz?= =?utf-8?B?SStheTRFVEpvSkpIMjI4aWtESmNIdDF0a3MxYkUzUU45ZlBORnM2b2IvcjY3?= =?utf-8?B?RE9VR004M3JmRkxqaUxOSW1JakVtZ2t0WU1UT21leDdhWTVmZWNValZHeTNo?= =?utf-8?B?NUd4b3MwbnRJdWlySndybjZxQVhNZ2MxMDNZTUVpN3JQQXZZZVh0M1M0Mk1J?= =?utf-8?B?ZVRpWUtHaSsyYUgxYkNhWWFoOUI0V081cGh5SEtldFp3ZVlXSzB1WlJSbW50?= =?utf-8?B?LzhXT1U1VGxvcGJSVmRmOW5LMGVHTDJzbEExQUtMSmlyWmhYMi82Z3ZZQ3lP?= =?utf-8?B?a1FrNklYOERyY2xVemJxR25OWDExTWN0RjhyZ1RFYm00UU11djJDZzRHOXRn?= =?utf-8?B?M0dlb0pmK1lPcmhBdVgweE9vYllJRE4vQ01VdFhodksrNFcxL1Z4dzdURkIx?= =?utf-8?B?NlJxU1pjQkFUZXNkdGhhaGNvUXJoOUl6OUlFaWVPK1B3R09Yb3FsWWhMbnJw?= =?utf-8?B?R09BTnNYR0hkemdLL0t0VFpOQ1ZNcDZ1bGd5K2l3NlFOcnR2cEVUaXRSbitv?= =?utf-8?B?M2FLaGJ1cVdCK0Fnbmt6ZEoyQ0pHN2FnbDNyakNNVmJPODNwSGhCVXppVGF3?= =?utf-8?B?b04vbVlHV2UxUHJvK0pMeUNYa3RmNzJCMkFoeDd2SEIvd2dQQXF2aDNkS0JR?= =?utf-8?B?VXc2N0FtajgwOEludXQrdFUxWUNJbWtHZFkvNmRhcDZnNHBGbS95eDZ0cTAz?= =?utf-8?B?bkd3Rmg4OEwyZUw5R2pVM0lCL2xkcFlsYkJoNHpFdWxMcmx5c2g3YnBXN2Np?= =?utf-8?B?TmZ0VkhqS3d0My9LNnVKMU5ic2NTVEtTOThtTURQekNxUVJEUGhzTGUrdnY5?= =?utf-8?B?VXNCeU5lVThsMmF5YlU2TUo0OHI1RE54WHJxaElVZEtSaDhONngyaDFDYkhO?= =?utf-8?B?V3R3SGFGTitBYitjUlFVNFJZVzJhZE80VllFZDVQMG4zMWhCeXE2SnBRVzNF?= =?utf-8?B?ajNBQjFrUzdrN1JzZ1VnRTAzWTB1UzBvKy9YWWZWa1Q5UWt0RVFyQ3pYM3V6?= =?utf-8?B?dUZtSG0ybk1XOXRPc1BKSUYrWjdXQU96dDVBY3JEbTJMTk9UWkZTcE5sTHBt?= =?utf-8?B?TTNmM0tnakJFa0R0OGFhVmJTeE5XeS84T2RPVk9pYzR5UmVZTDFybjZEdVNJ?= =?utf-8?Q?ZnGjU94klzNQ2UO1Bg=3D?=
x-ms-exchange-transport-forked: True
Content-Type: multipart/alternative; boundary="_000_MWHPR18MB10533260740A2FF65559CBC4E9429MWHPR18MB1053namp_"
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: MWHPR18MB1053.namprd18.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: d4d89b1d-bab1-44d5-2cb5-08d908953a45
X-MS-Exchange-CrossTenant-originalarrivaltime: 26 Apr 2021 09:25:26.6129 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 0f7367b1-44f7-45a7-bb10-563965c5f2e5
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: H8ZiYJFgt33tRTola3UpnXYWtctlQogSyvihdldwU8B3q0ZYr26XZXOYBRXR064l/vV04MRkOLD4fTUGbimZ1XyOyCoM9tbSK2T4W999bys=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW3PR18MB3577
X-OriginatorOrg: belden.com
X-TM-AS-Product-Ver: SMEX-14.0.0.1158-8.6.1012-26114.006
X-TM-AS-Result: No-10--19.986100-8.000000
X-TMASE-MatchedRID: JQSF04SbSlTevf2qR5u0IYHR2ZrOkgW3/bCauXgNPxRM+dGq778Y1mef QAfaVEc5GUlF/M3Dxp8XyU2Cxtlxbze8NM6rHHeC+/KqneiC8jbXuXIDKCy/Si3CNIOVjHOvvXt lm87JVdoZ9MKxHrUy4aVjgXyvS9c/qRTAHcwAECc0FvmldLRfXjYhG5T4PWdAnTzGzYHhxFRri1 aqkTqJcJIxx4WPBnUTYw5laZwLKuw/EkU1ffkoT1DvlvVG7MPYxF2xiZdnBH/JCsAmRhWgm3Y8h 0p1oFuRhg76h8s/HWsO8pJojG7qSmmj1qXcLu1ix8j1czHLBgKJkd0stjH9yb6Aix/my4wCwXNg pwKz1xEBNsbwZuG8YBHqvnsZ739IyRNOK11u4l3W3b0otYpGPiXk4Aj4K76wkRGShqSzBVnserF RQKzxaoR4m9rj7TBdxVGe6vB6kBSNnAdfrf4ZXibN560aM+0koN0RQvVLvuASrtEk8s4B7/6jo8 rINCnI8oVR2HfPs/SlGCIMbr7g/n0ZPjJ71o3uLPJtWpbJjY0Y4+H11kDdUJtxO5EVwbw8PWKLA 6/g//s4zRqVgiL30xMCOhxbOH51dVwkk1PJfl2p/Q97frGQaO/UvEaa2ZN4QqsbT9osOqtJWn0l qwnLd07yqWc5cVLPktxvVMaWMbB1x9TrfLzE8PtN2vjEPERNRRa406V/YwwRidIEWMkkVXItegU 8T6xV/0/qM4UIzlzIEQTlh1/QMTTMRkuw8aulBoGhV1TduQFOgw4ZVbmEe7zi4gATVmXCXe8I24 enWzWdVNZaI2n6/wwHQlYiLs1AlwV2iaAfSWfSBVVc2BozSlkMvWAuahr8fhPTr/QlfLbC3mjfc 0j3ZrDGGXOPbPCb4x1M+h9p88AuKiZT7iqpYhOjSm5EUmHDWUxaQOqQOltgO21BQaodlQ==
X-TM-AS-User-Approved-Sender: No
X-TM-AS-User-Blocked-Sender: No
X-TMASE-Result: 10--19.986100-8.000000
X-TMASE-Version: SMEX-14.0.0.1158-8.6.1012-26114.006
X-TM-SNTS-SMTP: 3D6FC0EEED474B13B502C26A51EC902A11714393EE9FF72E1F1CAB13478895FE2000:8
X-C2ProcessedOrg: 157cf0a0-3349-4636-89a5-bb6917ccdf3c
X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391, 18.0.761 definitions=2021-04-25_11:2021-04-23, 2021-04-25 signatures=0
Archived-At: <https://mailarchive.ietf.org/arch/msg/detnet/F6gV-aB5TpgxtgHVICFz-PXL0nk>
Subject: Re: [Detnet] Packet Ordering Function (draft-varga-detnet-pof-00.txt)
X-BeenThere: detnet@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Discussions on Deterministic Networking BoF and Proposed WG <detnet.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/detnet>, <mailto:detnet-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/detnet/>
List-Post: <mailto:detnet@ietf.org>
List-Help: <mailto:detnet-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/detnet>, <mailto:detnet-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 26 Apr 2021 09:25:42 -0000

Hi Greg,

Looking at the scenario you describe I think packets arriving in the order 100, 103, 102, 101 cannot happen due to an error on the transmission path if you are using only two paths. They might happen if the sender is failing and sends out the packets in the wrong order to begin with or if you are using more than two paths for redundancy and have failures on multiple transmission paths in a very specific order.
That being said, even then the transmission order 100, 101, 103, 102 should not be something you get from the POF in my opinion. If the packets are arriving and are buffered the way you describe, I think the following is what should happen (changes to what you had in your mail marked in red):

  *   POFLastSent = 100
  *   a packet with seq_num = 103 is received and placed into the buffer for the duration of POFMaxDelay
  *   next received packet has seq_num = 102. It is also moved into the buffer for the duration of POFMaxDelay
  *   finally, before all delayed packets transmitted out of the buffer, a packet with seq_num = 101 is received and is forwarded right away. This sets POFLastSent = 101.
  *   the packet with seq_num=102 is forwarded because it now fulfills the condition ‘OR its seq_num becomes equal to"POFLastSent + 1"’. This sets POFLastSent = 102.
  *   the packet with seq_num=103 is forwarded because it now fulfills the condition ‘OR its seq_num becomes equal to"POFLastSent + 1"’. This set POFLastSent = 103.
  *   Packets arriving after that are forwarded without delay if they are next in sequence, and delayed if they are out of sequence as described in the POF algorithm.
Regards,
Stephan
--
Mit freundlichen Grüßen | With kind regards

Stephan Kehrer | Senior Architect – CTO Office | Hirschmann Automation and Control GmbH
Stuttgarter Straße 45-51 | 72654 Neckartenzlingen | Germany
Phone: +49 7127 14 - 1035 | Mobile: +49 152 28813002 | Fax: +49 7127 14 - 1600
stephan.kehrer@belden.com<mailto:stephan.kehrer@belden.com> | www.beldensolutions.com<http://www.beldensolutions.com/> | www.blog.beldensolutions.com<http://www.blog.beldensolutions.com/>

Hirschmann Automation and Control GmbH, Neckartenzlingen
Register Court: Stuttgart, Trade Register No.: HRB 225927
VAT No.: DE 814 212 604
Managing Director: Brian Anderson, Wolfgang Schenk, Brian Lieser



Von: detnet <detnet-bounces@ietf.org> Im Auftrag von Greg Mirsky
Gesendet: Samstag, 24. April 2021 03:04
An: Balázs Varga A <balazs.a.varga=40ericsson.com@dmarc.ietf.org>
Cc: detnet@ietf.org
Betreff: [EXTERNAL] Re: [Detnet] Packet Ordering Function (draft-varga-detnet-pof-00.txt)


External Message:Use caution before opening links or attachments
Hi Balazs,
thank you for the well-designed mechanism of one of the key DetNet functions.
I have a scenario and would appreciate your consideration if you think it is a plausible one:

  *   assume that POFLastSent = 100
  *   a packet with seq_num = 103 is received and placed into the buffer for the duration of POFMaxDelay
  *   next received packet has seq_num = 102. It is also moved into the buffer for the duration of POFMaxDelay
  *   finally, before all delayed packets transmitted out of the buffer, a packet with seq_num = 101 is received and is forwarded right away
  *   the delay timer expires on the packet with seq_num=103. It is forwarded and  POFLastSent = 103
  *   next, the delay timer expires on the packet with seq_num=102. It, in turn, is forwarded and  POFLastSent = 102
  *   from now, based on my understanding of the described POF algorithm, every packet will be delayed even if there are no re-ordered packets. For example, the sequence of arriving packets is as 104, 105, 106, ...
Much appreciate your opinion if the scenario, i.e., a sequence like 100, 103, 102, 101, is a realistic one.

Regards,
Greg

On Mon, Apr 19, 2021 at 10:39 PM Balázs Varga A <balazs.a.varga=40ericsson.com@dmarc.ietf.org<mailto:40ericsson.com@dmarc.ietf.org>> wrote:
Hi,

A draft on Packet Ordering Function (POF) algorithms were uploaded.
Comments and views are highly appreciated.

Thanks
Bala'zs (and the authors)

-----Original Message-----
From: internet-drafts@ietf.org<mailto:internet-drafts@ietf.org> <internet-drafts@ietf.org<mailto:internet-drafts@ietf.org>>
Sent: Tuesday, April 20, 2021 7:14 AM
To: Balázs Varga A <balazs.a.varga@ericsson.com<mailto:balazs.a.varga@ericsson.com>>; Janos Farkas <Janos.Farkas@ericsson.com<mailto:Janos.Farkas@ericsson.com>>; Balázs Varga A <balazs.a.varga@ericsson.com<mailto:balazs.a.varga@ericsson.com>>; Janos Farkas <Janos.Farkas@ericsson.com<mailto:Janos.Farkas@ericsson.com>>; Stephan Kehrer <Stephan.Kehrer@belden.com<mailto:Stephan.Kehrer@belden.com>>; Stephan Kehrer <stephan.kehrer@belden.com<mailto:stephan.kehrer@belden.com>>; Tobias Heer <Tobias.Heer@belden.com<mailto:Tobias.Heer@belden.com>>; Tobias Heer <tobias.heer@belden.com<mailto:tobias.heer@belden.com>>
Subject: New Version Notification for draft-varga-detnet-pof-00.txt


A new version of I-D, draft-varga-detnet-pof-00.txt has been successfully submitted by =?utf-8?q?Bal=C3=A1zs_Varga?= and posted to the IETF repository.

Name:           draft-varga-detnet-pof
Revision:       00
Title:          Deterministic Networking (DetNet): Packet Ordering Function
Document date:  2021-04-19
Group:          Individual Submission
Pages:          10
URL:            https://www.ietf.org/archive/id/draft-varga-detnet-pof-00.txt<https://urldefense.com/v3/__https:/www.ietf.org/archive/id/draft-varga-detnet-pof-00.txt__;!!B_EDKQmmvsU!7vmDpLfsfmmLuG9tQHwCrsPqlNqL_fA88lGK7awH9s4iu2A-gZ-KVq6uPhKWdzZ8c98$>
Status:         https://datatracker.ietf.org/doc/draft-varga-detnet-pof/<https://urldefense.com/v3/__https:/datatracker.ietf.org/doc/draft-varga-detnet-pof/__;!!B_EDKQmmvsU!7vmDpLfsfmmLuG9tQHwCrsPqlNqL_fA88lGK7awH9s4iu2A-gZ-KVq6uPhKWJABOkBc$>
Htmlized:       https://datatracker.ietf.org/doc/html/draft-varga-detnet-pof<https://urldefense.com/v3/__https:/datatracker.ietf.org/doc/html/draft-varga-detnet-pof__;!!B_EDKQmmvsU!7vmDpLfsfmmLuG9tQHwCrsPqlNqL_fA88lGK7awH9s4iu2A-gZ-KVq6uPhKWE_vUf0k$>
Htmlized:       https://tools.ietf.org/html/draft-varga-detnet-pof-00<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-varga-detnet-pof-00__;!!B_EDKQmmvsU!7vmDpLfsfmmLuG9tQHwCrsPqlNqL_fA88lGK7awH9s4iu2A-gZ-KVq6uPhKW2P84vhs$>


Abstract:
   Replication and Elimination functions of DetNet [RFC8655] may result
   in out-of-order packets, which may not be acceptable for some time-
   sensitive applications.  The Packet Ordering Function (POF) algorithm
   described herein enables to restore the correct packet order when
   replication and elimination functions are used in DetNet networks.




Please note that it may take a couple of minutes from the time of submission until the htmlized version and diff are available at tools.ietf.org<https://urldefense.com/v3/__http:/tools.ietf.org__;!!B_EDKQmmvsU!7vmDpLfsfmmLuG9tQHwCrsPqlNqL_fA88lGK7awH9s4iu2A-gZ-KVq6uPhKWhEGXwQU$>U$>.

The IETF Secretariat


_______________________________________________
detnet mailing list
detnet@ietf.org<mailto:detnet@ietf.org>
https://www.ietf.org/mailman/listinfo/detnet<https://urldefense.com/v3/__https:/www.ietf.org/mailman/listinfo/detnet__;!!B_EDKQmmvsU!7vmDpLfsfmmLuG9tQHwCrsPqlNqL_fA88lGK7awH9s4iu2A-gZ-KVq6uPhKWTJ53qCw$>

**********************************************************************
DISCLAIMER:
Privileged and/or Confidential information may be contained in this message. If you are not the addressee of this message, you may not copy, use or deliver this message to anyone. In such event, you should destroy the message and kindly notify the sender by reply e-mail. It is understood that opinions or conclusions that do not relate to the official business of the company are neither given nor endorsed by the company. Thank You.