It's my understanding, at least in the 7.x train of Cisco wireless, that
multicast data is transmitted at the highest basic (required) rate. Management
frames can also be set to use the highest basic rate and/or kept at the lowest
basic rate. Of course, transmitting at the highest basic rate does require
smaller cell sizes.
There is no client limit that I'm aware of, but even if it was 12 like Aruba,
my cells are small enough that it would be rare to see that many clients on a
single radio.
Cisco also introduced a new multicast optimization in 7.0.116, so when using
VLAN pooling, you wind up with only a single multicast stream no matter how
many VLANs are in the pool. This is a big plus if say you have 10 clients all
on the same AP, but all in different VLANs. Instead of 10 copies (1 per VLAN)
of the multicast stream going out over the air, there is only one that all
clients listen to.
Jeff
>>> On Wednesday, February 22, 2012 at 9:49 AM, in message
>>> <cb6a92f7.2586b%stan.bro...@emory.edu>, "Brooks, Stan"
>>> <stan.bro...@emory.edu> wrote:
So it's not just about the bandwidth. B'cast & M'cast use the lowest
configured data rate of the AP - just like wireless management frames.
This means that even for 300Mbps 802.11n network is reduced to 24Mbps or
less. That also ties up airtime that could be given to faster clients as
well, since transmitting data at a lower data rate consumes more time that
transmitting data at a higher data rate.
So even if it is a low bit-rate stream, it takes away more available
bandwidth from other clients.
Aruba has a method that takes b'cast & m'cast and converts it to higher
speed unicast traffic to each client. This gives better results for about
up to 12 clients on an AP/radio.
>>-> Stan Brooks - CWNA/CWSP
Emory University
University Technology Services
404.727.0226
AIM/Y!/Twitter: WLANstan
MSN: wlans...@hotmail.com
GoogleTalk: wlans...@gmail.com
-----Original Message-----
From: Mike Goebel <michael.goe...@wmich.edu>
Reply-To: The EDUCAUSE Wireless Issues Constituent Group Listserv
<WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Date: Wed, 22 Feb 2012 11:09:16 -0500
To: <WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] You knew it was coming...Airplay/Apple TV
support for instructors.
>Has anyone actually tracked how much bandwidth/usage Bonjour coughs up
>across their wlan infrastructure? I haven't analyzed it, and while it
>could be bandwidth hungry, it appears to me that will be more with
>device to device.
>
>I'm playing devils advocate here, but is a 6 meg stream on an N access
>point both ways really going to be crunching anyone? I'd be worried
>about G yes, but N with a gig uplink?
>
>I do find it unnerving that all the bonjour devices are able to find
>each other and potentially create a lot of traffic, but 99.9% of the
>time I don't see anyone working any access point very hard.
>
>Mike Goebel
>Network Programmer
>Office of Information Technology
>Western Michigan University
>Phone: 269-387-0453
>Email: michael.goe...@wmich.edu
>
>On 2/22/2012 10:18 AM, Kellogg, Brian D. wrote:
>> We will need Bonjour in order to allow faculty members to mirror their
>>iPads/WhateverAppleProductElse to an AppleTV in a classroom for
>>presentations wirelessly. Presently we block all mcast and bcast on our
>>WLAN due to the channel use overhead this incurs (anywhere from 10% to
>>20%). We'll be moving to Aruba this summer where enabling bcast and
>>mcast is not an all or nothing endeavor I believe. I think Aruba is
>>integrating some stuff into their controller code to help with this
>>problem or already has it. Someone who knows more about Aruba can
>>correct me if I'm wrong.
>>
>> -Brian
>>
>> -----Original Message-----
>> From: The EDUCAUSE Wireless Issues Constituent Group Listserv
>>[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Brian David
>> Sent: Wednesday, February 22, 2012 10:11 AM
>> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
>> Subject: Re: You knew it was coming...Airplay/Apple TV support for
>>instructors.
>>
>> We are faced with the same issues here at BC... We are starting to
>>block it for all students but have not for the Faculty.
>> Could you give more details on what apps the faculty needed bonjour for?
>> -Brian
>>
>> Brian J David
>> Network Systems Engineer
>> Boston College
>>
>>
>> -----Original Message-----
>> From: The EDUCAUSE Wireless Issues Constituent Group Listserv
>>[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Brian Helman
>> Sent: Wednesday, February 22, 2012 9:54 AM
>> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
>> Subject: Re: [WIRELESS-LAN] You knew it was coming...Airplay/Apple TV
>>support for instructors.
>>
>> Agreed. We are blocking bonjour between buildings, but not within. I
>>wanted to block within, but there are apps out there that the faculty
>>want to use that require it. That was the compromise I settled on...
>>looking forward to 802.11ac now.
>>
>> I thought my days of dealing with AppleTalk, IPX and Netbeui were done.
>>
>> -Brian
>>
>> -----Original Message-----
>> From: The EDUCAUSE Wireless Issues Constituent Group Listserv
>>[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Kellogg, Brian
>>D.
>> Sent: Tuesday, February 21, 2012 5:21 PM
>> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
>> Subject: Re: [WIRELESS-LAN] You knew it was coming...Airplay/Apple TV
>>support for instructors.
>>
>> Had an Apple rep in recently and he stated Apple (Bonjour) has come a
>>long way since Appletalk on their network protocols. I wanted to
>>believe him and then I tried to use it on our campus. LAN only protocol
>>that relies on mDNS registration to bridge networks assuming all your
>>end devices support it of course. Reminds me of LAN/SOHO only protocols
>>I worked with a decade ago. Why not allow the device being mirrored to
>>specify the device you want to mirror to by IP address or FQDN. I don't
>>think I'm asking for too much from the man but, alas, perhaps I am.
>>
>>
>> Disappointed yet again by Apple network protocols, Brian
>>
>> -----Original Message-----
>> From: The EDUCAUSE Wireless Issues Constituent Group Listserv
>>[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Lee H Badman
>> Sent: Tuesday, February 21, 2012 4:57 PM
>> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
>> Subject: Re: You knew it was coming...Airplay/Apple TV support for
>>instructors.
>>
>> Would be interesting to contemplate a petition or similar from the
>>Educause members to Apple requesting that they catch up to the fact that
>>their toys are invading the enterprise, that the enterprise doesn't run
>>on AirPorts, and therefor they might develop towards the enterprise
>>WLAN, Then again, I doubt they'd give a rip.
>>
>> It's a shame that the sexiest devices on the planet have such shallow
>>network development behind them.
>>
>> -Lee
>>
>>
>> ________________________________________
>> From: The EDUCAUSE Wireless Issues Constituent Group Listserv
>>[WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] on behalf of Cappalli, Tim G @
>>LSC-ITS [tim.cappa...@lsc.vsc.edu]
>> Sent: Tuesday, February 21, 2012 4:36 PM
>> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
>> Subject: Re: [WIRELESS-LAN] You knew it was coming...Airplay/Apple TV
>>support for instructors.
>>
>> It's time for Apple step up. How many hundreds of hours are we going to
>>spend on this? For the first time in a long time, we are saying "no" for
>>the time being.
>>
>>
>> Tim Cappalli, CCNA ACMA | IT Services | (802) 626-6456
>>> tim.cappa...@lyndonstate.edu | it.lyndonstate.edu
>>
>> PRIVACY& CONFIDENTIALITY NOTICE
>> This message is for the designated recipient only and may contain
>>privileged, confidential, or otherwise private information. If you have
>>received it in error, please notify the sender immediately and delete
>>the original. Any other use of an email received in error is prohibited.
>>
>> Sent from my BlackBerry(r) PlayBook(tm)
>>
>> -----Original Message-----
>> From: The EDUCAUSE Wireless Issues Constituent Group Listserv
>>[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Peter P
>>Morrissey
>> Sent: Tuesday, February 21, 2012 4:14 PM
>> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
>> Subject: Re: [WIRELESS-LAN] You knew it was coming...Airplay/Apple TV
>>support for instructors.
>>
>> Isn't it amazing that they actually mention classrooms and conference
>>rooms here, yet the geniuses at Apple probably have no clue about what
>>is really involved?
>> Pete M.
>>
>> -----Original Message-----
>> From: The EDUCAUSE Wireless Issues Constituent Group Listserv
>>[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Julian Y Koh
>> Sent: Tuesday, February 21, 2012 4:00 PM
>> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
>> Subject: Re: [WIRELESS-LAN] You knew it was coming...Airplay/Apple TV
>>support for instructors.
>>
>> -----BEGIN PGP SIGNED MESSAGE-----
>> Hash: SHA1
>>
>> On Fri Dec 16 2011 11:16:43 Central Time, "Johnson, Neil M" wrote:
>>>
>>> We have a request to support Airplay/Apple TV's on our enterprise
>>> network so that instructors can mirror presentations from their iPad's
>>> to classroom and meeting room projectors.
>>
>> This is only going to get more prevalent now that Mountain Lion will
>>support Airplay mirroring from OS X machines.
>>
>> <http://www.apple.com/macosx/mountain-lion/features.html#airplay>
>>
>> Gonna be fun....
>>
>> - --
>> Julian Y. Koh<mailto:kohs...@northwestern.edu>
>> Manager, Network Transport<phone:847-467-5780>
>> Telecommunications and Network Services Northwestern University
>> PGP Public Key:<http://bt.ittns.northwestern.edu/julian/pgppubkey.html>
>>
>> -----BEGIN PGP SIGNATURE-----
>> Version: GnuPG/MacGPG2 v2.0.17 (Darwin)
>> Comment: GPGTools - http://gpgtools.org
>>
>> iEYEARECAAYFAk9EBcgACgkQDlQHnMkeAWMf8wCfdfVsWgcll4cqUiIQRL/DClf5
>> w1IAnjvdC0e34jam3rguhn2fG/kUmm+p
>> =Bd3x
>> -----END PGP SIGNATURE-----
>>
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