Wireless Multimedia (WMM) question

When using WMM-certified network cards, will all my audio/video
applications get automatically higher priority in the network or these
applications have to support WMM? If for using the advantages of WMM,
the multimedia applications have to be WMM-aware, do you know any
information about what audio/video applications currently support WMM?

Thank you very much!!
Alex.


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qnx escribió:
> When using WMM-certified network cards, will all my audio/video
> applications get automatically higher priority in the network or these
> applications have to support WMM? If for using the advantages of WMM,
> the multimedia applications have to be WMM-aware, do you know any
> information about what audio/video applications currently support WMM?
>
> Thank you very much!!
> Alex.
>
>
> ------------------------------------------------------------------------
> View this thread: http://www.wirelessforums.org/showthread.php?t=26003
> http://www.wirelessforums.org
>

Hi Alex,

that's a good question. I really don't know the exact answer but 802.11x
is a Link Layer protocol and Link Layer software talks with Network
layer one.

With that premise, Network Layer software should insert traffic in the
proper queue to make use of QoS capabilities of WMM-certified hardware
in function of its origin (or traffic class).

By the same rule, applications should notify Network Layer software (or
whatever intermediate layer) what class of traffic is trying to send.

I don't know if intermediate layers made a mapping of traffic or
application must explicityly notify it.

I guess somebody can help us with this excellent question.

Best regards.

qnx <(E-Mail Removed)> hath wroth:

>When using WMM-certified network cards, will all my audio/video
>applications get automatically higher priority in the network or these
>applications have to support WMM? If for using the advantages of WMM,
>the multimedia applications have to be WMM-aware, do you know any
>information about what audio/video applications currently support WMM?

The QoS (Quality of Service) part is right out of 802.11e. Very
crudely, it assigns a priority to various protocols, ports, apps, or
whatever. It crams the highest priority packets into the contention
interval between low prioirty packets.

What you're really asking is how these priorities are assigned. It's
NOT automagic. The router is not expected to be able to detect and
distinguish various applications as they dribble through. You have to
do it manually in the router.

For example, the QoS/WMM support on the Linksys WRV200 is rather
minimal and crude. See the settings at:
<http://www.linksysdata.com/ui/WRV200/1.0.29/AppQos.htm>
You pick a port number that is used by the application, and assign it
a priority. There are really 16 levels of priority, but Linksys only
offers 2.

A more complete implimentation is WMM on DD-WRT:
<http://www.linksysinfo.org/forums/showthread.php?t=47262>
Noticed that there are no settings for the name or type of
application. Just "audio" and "video". This is strictly for setting
how the QoS system works. The actual priority for a given application
gets set on the QoS page such as:
<http://www.informatione.gmxhome.de/DDWRT/Standard/V23final/QoS.html>
(Check "Enable QoS" and click on the
Services Priority -> Add/Edit Service
button. Note that you have to specify the port numbers. Some details
and sample settings:
<http://www.dd-wrt.com/wiki/index.php/Quality_of_Service>

Note that Wireless QoS is different from LAN QoS.
<http://www.cisco.com/univercd/cc/td/doc/product/access/mar_3200/mar_wbrg/o13qos.htm#wp1042166>
However, there is enough commonality that most routers just mix them
both together on the same settings page. Oh well.

QoS and WMM can also be implimented in the client operating system.
See:

WiFi QoS in Windoze Vista (4 parts):
<http://blogs.msdn.com/wndp/archive/2006/06/28/650363.aspx>
<http://blogs.msdn.com/wndp/archive/2006/06/30/WiFi-QoS-Support-in-Windows-Vista-part-2.aspx>
<http://blogs.msdn.com/wndp/archive/2006/07/21/674419.aspx>
<http://blogs.msdn.com/wndp/archive/2006/08/09/WiFi-QoS-Support-in-Windows-Vista-part-4.aspx>

Microsoft QoS pages:
<http://www.microsoft.com/technet/network/qos/default.mspx>

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558