Subject: [v6ops] IPv6 multicast WiFi power usage - draft-desmouceaux-ipv6-mcast-wifi-power-usage

From: Andrew Yourtchenko <[email-masked]>
Date: Fri, 11 Jul 2014 15:16:19 +0200

hi all,

last IETF there were presentations about ND, multicast and power usage on 
the WiFi, the consensus was we need more data on it.

Yoann did a nontrivial amount of work on this subject in the meantime and 
we'd like to show it to you and hear your feedback.

http://tools.ietf.org/html/draft-desmouceaux-ipv6-mcast-wifi-power-usage-00

thanks a lot!

--a

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From: "STARK, BARBARA H" <[email-masked]>
Date: Fri, 11 Jul 2014 16:13:41 +0000

Thanks for sharing. This is a very good thought-provoking paper, and I'm impressed with the research that was done.

An assumption I'd like to challenge is the one that putting multicast snooping on router/AP Wi-Fi interfaces is "costly in terms of resources and complexity for small systems like home boxes". I have some experience in requiring this of CE router vendors (it's absolutely required in CE routers that support IPTV services because we can't have huge multicast streams flooding the Wi-Fi connection when a single Wi-Fi device joins a stream). While other aspects of multicast handling have proven difficult to get right (IGMP proxy between WAN and LAN), the snooping on the Wi-Fi interface has not proven to be a problem. My personal suspicion is that "costly in terms of resources and complexity" is an excuse given by those who don't want to put in the effort to actually look into and do it. I also suspect that it would be holistically more cost-effective to put multicast snooping on router/AP Wi-Fi interfaces than to put the L2 multicast filter on all end devices (one of the options described in the paper).
Barbara

> -----Original Message-----
> From: v6ops [mailto:[email-masked]] On Behalf Of Andrew
> Yourtchenko
> Sent: Friday, July 11, 2014 9:16 AM
> To: [email-masked]
> Cc: [email-masked]
> Subject: [v6ops] IPv6 multicast WiFi power usage - draft-desmouceaux-ipv6-
> mcast-wifi-power-usage
> 
> hi all,
> 
> _______________________________________________
> v6ops mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/v6ops

---

From: Alejandro Acosta <[email-masked]>
Date: Sat, 12 Jul 2014 06:28:48 -0430

Hello,
  Very nice draft and very interesting results. While reading it I was
thinking that certain drafts could include something like a "Enviroment
friendly section".

Alejandro,

El 7/11/2014 8:46 AM, Andrew Yourtchenko escribió:
> hi all,
> 
> last IETF there were presentations about ND, multicast and power usage
> on the WiFi, the consensus was we need more data on it.
> 
> Yoann did a nontrivial amount of work on this subject in the meantime
> and we'd like to show it to you and hear your feedback.
>

---

From: Andrew Yourtchenko <[email-masked]>
Date: Mon, 14 Jul 2014 11:22:02 +0200

Alejandro,

interesting idea. Could you elaborate a bit more ? I'm guessing it would 
be something to do with the power consumption, but estimating the power 
consumption in the generic case is really really tricky, so I am wondering 
how this kind of section might look like to be useful.

thanks!

--a

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From: Alejandro Acosta <[email-masked]>
Date: Tue, 15 Jul 2014 05:45:21 -0430

Hi Andrew,
  My only comment inline:

El 7/14/2014 4:52 AM, Andrew Yourtchenko escribió:
> consumption in the generic case is really really tricky, so I am
> wondering how this kind of section might look like to be useful.

  Thanks for asking, in fact after I sent I got stuck thinking in this
topic.
  While reading
http://tools.ietf.org/html/draft-desmouceaux-ipv6-mcast-wifi-power-usage-00
 I was thinking that probably some drafts or documents might include an
environmental section which should be related to green stuff such as
power consumption and things no harmful for the environment.
  Trying to elaborate a bit more the idea would be something very
similar to the current Security section which is mandatory. If we
include an environmental section it could help IETF to develop better
and more friendly protocols to the environment. Is it time to do it?,
  If we want to be idealistic low power consumption should be encourage
in all areas -not only mobile-, devices should be able to get in sleep
mode without affecting the network and much more (CPU processing, etc).

My 2 cents,

Alejandro,

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From: Nabil Benamar <[email-masked]>
Date: Wed, 23 Jul 2014 12:26:21 +0000

Hi Yoann,

I really like your draft related to IPv6 multicast. Your current work could
become also a good research paper to be submitted to a good journal for
publication!

 As said in the Abstract: "Although the use of multicast does not create
real difficulties on wired networks, it can become painful on wireless
ones, notably in terms of power consumption" . This is a huge problem in
the case of constrained devices such in the Internet of Things. If the
sensors are in sleep mode they will nor receive all multicast messages and
then their IPv6 connectivity and performances could become intermittent !!

So in the introduction " this can have a negative impact on low-energy
devices such as

smartphones, as stated in [I-D.vyncke-6man-mcast-not-efficient]. The

802.11 protocol [IEEE80211]"  you can also mention the case of the
constrained devices (IoT) and the LLN (Low Power Lossy Networks).

more to come...

*Best wishes*
*نبيل بنعمرو*
*Nabil Benamar*
*Moulay Ismail University.*
*Meknes. Morocco*
*nabilbenamar.com <http://nabilbenamar.com>*

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From: Chuck Anderson <[email-masked]>
Date: Wed, 23 Jul 2014 19:30:56 -0400

IPv6 multicast DOES appear to cause problems for wired networks too.
This guy experienced MLD reports being sent for 350 solicited node
multicast groups by a single Windows box with 350 Privacy Addresses in
use:

http://blog.bimajority.org/2014/07/16/ipv6-privacy-addresses-windows-just-say-no/

"Apparently the Windows implementation is more aggressive, or Windows
applications are more likely to hold connections open, because there
are lots of reports of Windows machines having hundreds of these
“privacy” addresses simultaneously — and that’s what appears to be
happening on our problem machine: every time the router sent out a
“please tell me all your memberships in the next 10 seconds” message,
the Windows box would reply with 30 MLD responses a second for ten
seconds."

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From: Mark Boolootian <[email-masked]>
Date: Wed, 23 Jul 2014 16:48:22 -0700

> multicast groups by a single Windows box with 350 Privacy Addresses in

Can privacy addresses be completely eliminated through the use of
DHCPv6 (disabling SLAAC on the router)?

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From: Mikael Abrahamsson <[email-masked]>
Date: Sat, 26 Jul 2014 17:58:43 +0200 (CEST)

On Wed, 23 Jul 2014, Mark Boolootian wrote:

> Can privacy addresses be completely eliminated through the use of DHCPv6 
> (disabling SLAAC on the router)?

Well, depends on your definition of SLAAC, but yes. Send RAs with A-bit=0, 
M-bit=1 and your machines will only get addresses the DHCPv6 server gives 
out, and it could enforce only single address per host.

Now, not all devices support to get IA_NA via DHCPv6, so your success rate 
with this will vary with what devices you have if you try this in real 
life.

-- 
Mikael Abrahamsson    email: [email-masked]