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

Linus Lüssing <> Sat, 28 March 2020 19:33 UTC

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From: Linus Lüssing <>
To: Hitoshi Asaeda <>
Cc: Dino Farinacci <>,,, Mark Smith <>
Message-ID: <20200328193311.GL2357@otheros>
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Subject: Re: [pim] [Mcast-wifi] Issues with MLD and Android powersaving / sleep mode...
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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

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
    (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