Compressed Routing Header idea

"Templin (US), Fred L" <Fred.L.Templin@boeing.com> Mon, 18 May 2020 14:05 UTC

Return-Path: <Fred.L.Templin@boeing.com>
X-Original-To: ipv6@ietfa.amsl.com
Delivered-To: ipv6@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id AC3283A0C6A for <ipv6@ietfa.amsl.com>; Mon, 18 May 2020 07:05:11 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -0.199
X-Spam-Level:
X-Spam-Status: No, score=-0.199 tagged_above=-999 required=5 tests=[DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=boeing.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 oaymQmCVNvEH for <ipv6@ietfa.amsl.com>; Mon, 18 May 2020 07:05:09 -0700 (PDT)
Received: from phx-mbsout-01.mbs.boeing.net (phx-mbsout-01.mbs.boeing.net [130.76.184.178]) (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 6CA083A0FCF for <ipv6@ietf.org>; Mon, 18 May 2020 07:04:06 -0700 (PDT)
Received: from localhost (localhost [127.0.0.1]) by phx-mbsout-01.mbs.boeing.net (8.15.2/8.15.2/DOWNSTREAM_MBSOUT) with SMTP id 04IE43al052865; Mon, 18 May 2020 07:04:05 -0700
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=boeing.com; s=boeing-s1912; t=1589810645; bh=5PhMv6SgWyaGHjjy08mx6lp/jV7LYbu64UGtmuu9PMU=; h=From:To:Subject:Date:From; b=NldHpAQb1Md8UNf3uytKoAU/xCya7qSvGakHfT23LN9A+pNVACgcgyN68u6FXfRMg P1HwWWBDb660iR1P1YeQsYJs3MxmKJ9ZB+rPySvy2d/7EqMtY5UBUQc1796EeD37NN vCx/lezshhS6YsKo9I8jBfoOJI/Gb/uxu2gSdnqV2aQ/4WDsxVhxhnz/faPqj+slms vygo/51ooX89iKBqXvecgivIXbTmMdEnFTqbfDBoR6uoE596UFJuIIfH7jvtKz06w5 rHxtCgtpgnniv3Ok4b4WyyJTCa2n6Jfogs/BxFygtM7/jAOiDIAH25l6JbBhtixYxq bmUYyw+RPj9vw==
Received: from XCH16-07-08.nos.boeing.com (xch16-07-08.nos.boeing.com [144.115.66.110]) by phx-mbsout-01.mbs.boeing.net (8.15.2/8.15.2/8.15.2/UPSTREAM_MBSOUT) with ESMTPS id 04IE3vxA052694 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=OK) for <ipv6@ietf.org>; Mon, 18 May 2020 07:03:58 -0700
Received: from XCH16-07-10.nos.boeing.com (144.115.66.112) by XCH16-07-08.nos.boeing.com (144.115.66.110) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.1.1979.3; Mon, 18 May 2020 07:03:56 -0700
Received: from XCH16-07-10.nos.boeing.com ([fe80::e065:4e77:ac47:d9a8]) by XCH16-07-10.nos.boeing.com ([fe80::e065:4e77:ac47:d9a8%2]) with mapi id 15.01.1979.003; Mon, 18 May 2020 07:03:56 -0700
From: "Templin (US), Fred L" <Fred.L.Templin@boeing.com>
To: IPv6 List <ipv6@ietf.org>
Subject: Compressed Routing Header idea
Thread-Topic: Compressed Routing Header idea
Thread-Index: AdYtHG+8rC3YEibIRJu4gVbarLwgbQ==
Date: Mon, 18 May 2020 14:03:56 +0000
Message-ID: <2a844eb431b346b8931196c5e21d33ae@boeing.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [137.137.12.6]
x-tm-snts-smtp: 86EB7EA27826E6591890639271D59254E36F9C360C7EDBE146ED0C6B623895812000:8
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: base64
MIME-Version: 1.0
X-TM-AS-GCONF: 00
Archived-At: <https://mailarchive.ietf.org/arch/msg/ipv6/9HUpbjtIecwsP6Bm2uqnRjRptGE>
X-BeenThere: ipv6@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "IPv6 Maintenance Working Group \(6man\)" <ipv6.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ipv6>, <mailto:ipv6-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ipv6/>
List-Post: <mailto:ipv6@ietf.org>
List-Help: <mailto:ipv6-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ipv6>, <mailto:ipv6-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 18 May 2020 14:05:18 -0000

Hi, I have a use case where some IPv6 addresses that would go into a routing header are
more compressible than others and so I am wondering if some kind of "hybrid" compressed
routing header would be possible. For example, if one address can be compressed down to
16 bits, then include only those 16 bits; if a different address can only be compressed down
to 32 bits, then include the 32 bits; if yet a different address cannot be compressed at all,
then include all 128 bits. And, there may be many more sizes in between.

RFC4191 Section 2.3 shows an example of how an IPv6 prefix/address can be compressed
to a variable length. Essentially, a length byte followed by a variable-length prefix. That way
there would still be "pretty good compression" albeit with an extra byte per prefix. And, it
would be a generalized form that would only require a single routing header type value.
How would it be if we did something like that?

Fred