Re: [pim] [Mcast-wifi] Issues with MLD and Android powersaving / sleep mode...

Linus Lüssing <linus.luessing@c0d3.blue> Sat, 28 March 2020 19:33 UTC

Return-Path: <linus.luessing@c0d3.blue>
X-Original-To: pim@ietfa.amsl.com
Delivered-To: pim@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id BAEC63A0CEA; Sat, 28 Mar 2020 12:33:17 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -3.997
X-Spam-Level:
X-Spam-Status: No, score=-3.997 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_INVALID=0.1, DKIM_SIGNED=0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_NONE=0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=neutral reason="invalid (public key: not available)" header.d=c0d3.blue
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 t6x7CgbvwaWu; Sat, 28 Mar 2020 12:33:16 -0700 (PDT)
Received: from mail.aperture-lab.de (mail.aperture-lab.de [IPv6:2a01:4f8:171:314c::100:a1]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id B58523A0CE7; Sat, 28 Mar 2020 12:33:15 -0700 (PDT)
Date: Sat, 28 Mar 2020 20:33:11 +0100
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c0d3.blue; s=2018; t=1585423993; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=HUYmBlz8XLO5VcLMHKOLYlX0G/HHKDDuCP19cKI5zf4=; b=OgH0C/pOcDdRwMm3RAeCukhJQaJS/G/KzhDJo50LB49cRiWg3GkRfyMAdMAwmaTmZHER6q 8XwAbcsWMwCf50Giyxs5ipZ/UMfEQj7PclESNPdvJ9E7j8hU7UQzqnL/fdDw37yn9TwU/V qrxvdj7z4WKSjX9r/PqPptYEwWexoDzwEh5AgrBsQatBnj/YX7zUjyUFWKdaDdS+NOKuZl K+q1PWXhdAHaMwHcT97ekXYQS2o6pgidDaMuyFcDsgtslqWLvewJk0ZnyFoR0P4NgMm0ph 8odbW1Bh/Tq0R6+XQPNhy+5hOOhiaSppW0RwzsY++R/jZbCNOc610E/5AgQrPw==
From: Linus =?utf-8?Q?L=C3=BCssing?= <linus.luessing@c0d3.blue>
To: Hitoshi Asaeda <asaeda@ieee.org>
Cc: Dino Farinacci <farinacci@gmail.com>, mcast-wifi@ietf.org, pim@ietf.org, Mark Smith <markzzzsmith@gmail.com>
Message-ID: <20200328193311.GL2357@otheros>
References: <20200324205402.GD2357@otheros> <CAO42Z2zKxbJU85y9GT6tyF93MwbsXKWeFWRPAYXP6KHkn+L+8g@mail.gmail.com> <20200325113540.GF2357@otheros> <F20FA68B-ED13-4459-8DE7-83AD970D3BFD@gmail.com> <203AAA04-E7BA-4A21-8E66-D754A7CB823F@ieee.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <203AAA04-E7BA-4A21-8E66-D754A7CB823F@ieee.org>
Authentication-Results: ORIGINATING; auth=pass smtp.auth=linus.luessing@c0d3.blue smtp.mailfrom=linus.luessing@c0d3.blue
Archived-At: <https://mailarchive.ietf.org/arch/msg/pim/iBA8MQc2nCNpDvXSrkrnMEB5Ecc>
Subject: Re: [pim] [Mcast-wifi] Issues with MLD and Android powersaving / sleep mode...
X-BeenThere: pim@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Protocol Independent Multicast <pim.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/pim>, <mailto:pim-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/pim/>
List-Post: <mailto:pim@ietf.org>
List-Help: <mailto:pim-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/pim>, <mailto:pim-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sat, 28 Mar 2020 19:33:18 -0000

On Fri, Mar 27, 2020 at 07:19:34PM +0900, Hitoshi Asaeda wrote:
> RFC6636 (Tuning the Behavior of the Internet Group Management Protocol (IGMP) and Multicast Listener Discovery (MLD) for Routers in Mobile and Wireless Networks) gives some guideline to tune IGMP/MLD.
> Android and iOS implement some specific mechanisms to save battery power, hence I don't know if they work what we expect, though.

Oh, thanks! I didn't know about this RFC before. It's an interesting
read.

It's maybe not 100% what you were thinking of with "Explicit
Tracking of Membership Status", but it makes me wonder if the
following approach could help:

(1) We already track host and not just port based listener state
    for the Linux bridge "multicast-to-unicast" conversion feature
(2) We could avoid timing out host based multicast listener
    entries. And only remove such an entry in the following two
    cases:
    (i): The host vanishes in the Linux bridge FDB or
         even only if it vanishes on the 802.11 layer
    (ii): If an MLDv2 Report was received, but did
          not contain the specific multicast group anymore
    (iii): An MLDv1 Done was received for the specific group

Regards, Linus