Re: [Int-area] [pim] Fwd: [ieee-ietf-coord] draft on Multicast Considerations over IEEE 802 Wireless Media

Linus Lüssing <> Sun, 09 April 2017 10:37 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 35801128CFF; Sun, 9 Apr 2017 03:37:24 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.899
X-Spam-Status: No, score=-1.899 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id 2FxvE_wTctji; Sun, 9 Apr 2017 03:37:22 -0700 (PDT)
Received: from ( []) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id E174F129455; Sun, 9 Apr 2017 03:37:19 -0700 (PDT)
Received: from localhost (localhost []) by (Postfix) with ESMTP id 0840FE37AB; Sun, 9 Apr 2017 12:37:19 +0200 (CEST)
X-Virus-Scanned: Debian amavisd-new at
Received: from ([]) by localhost ( []) (amavisd-new, port 10025) with ESMTP id tPSTfD7n3E6l; Sun, 9 Apr 2017 12:37:18 +0200 (CEST)
Received: from localhost (unknown [IPv6:2001:67c:2d50:0:c85:8cff:fe0f:63fe]) (Authenticated sender: by (Postfix) with ESMTPSA; Sun, 9 Apr 2017 12:37:17 +0200 (CEST)
Date: Sun, 9 Apr 2017 12:37:16 +0200
From: Linus =?utf-8?Q?L=C3=BCssing?= <>
Cc:,, "Alvaro Retana (aretana)" <>
Message-ID: <20170409103716.GE10335@otheros>
References: <> <>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <>
User-Agent: Mutt/1.5.24 (2015-08-30)
Archived-At: <>
Subject: Re: [Int-area] [pim] Fwd: [ieee-ietf-coord] draft on Multicast Considerations over IEEE 802 Wireless Media
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: IETF Internet Area Mailing List <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Sun, 09 Apr 2017 10:37:24 -0000

> From: Juan Carlos Zuniga <<>>
> Date: March 31, 2017 at 8:33:01 AM CDT
> To:<>, Juan Carlos Zuniga <<>>
> Subject: [ieee-ietf-coord] draft on Multicast Considerations over IEEE 802 Wireless Media
> Hello all,
> This is the draft that I mentioned during the meeting. Please take a look and provide inputs either here or in the IntArea WG list (<>):

Hi everyone,

Thanks for raising awareness of the potential pitfalls concerning
multicast on 802.11! Had to find out about them the hard way back
then, so I am really looking forward to this RFC :).

My comment/wish is just about multicast group awareness: In
"3.2.3. - MLD issues" I would have expected some notes regarding
the issue of IGMP/MLD report suppression and how this makes it
difficult to track per STA group membership state.

I would have then expected a section regarding "Multicast Group
Awareness / Multicast Snooping" in "4 - Multicast protocol
optimizations", explaining how it can improve performance, but
what would need to be done to mitigate those report suppression
issues: If applying some multicast group awareness then how
RFC4541 would need to be translated from bridges to APs
(i.e. by interpreting each STA as an individual "switch port"
- and emphasizing again where to and where not to forward IGMP/MLD

An older version of OpenWRT missed RFC4541 for its group-aware
multicast-to-unicast implementation some years ago entirely,
resulting in ugly packetloss back then...

Regards, Linus