All things related to multicast

["Dale W. Carder" <>]

Hi Alan,

Yet another datapoint: I'll follow up with Xirrus.

Dale

On Apr 23, 2008, at 7:38 AM, Alan Crosswell wrote:

> Thanks, Rich.  Here's the updated list:
>
> Meru - Debbie Fligor, Paul Roberts
> Aruba - Doug Wilkinson
> Cisco - Paul Roberts, Alan Buxey
> HP ProCurve - Matt Davy
> Trapeze - Rich Ingram
> Ruckus - anybody have contacts? Simon Lockhart recommends talking to  
> them.
>
> /a
>
> Richard N. Ingram wrote:
> > Hello-
> >
> > I would be happy to take this up with Trapeze.  We are just beginning
> > our implementation and have already talked to them a bit about  
> > multicast.
> >
> > Best regards,
> > Rich
> >
> >
> > Alan Crosswell wrote:
> > > Thanks to everyone for volunteering.  What I have so far is:
> > >
> > > Meru - Debbie Fligor (Columbia uses Meru, so let me know if I can  
> > > help)
> > > Aruba - Doug Wilkinson
> > > Cisco & Meru - Paul Roberts
> > > HP ProCurve - Matt Davy
> > > Ruckus - anybody have contacts? Simon Lockhart recommends talking to
> > > them.
> > >
> > > This is a good start.
> > >
> > > /a
> > >
> > > Alan Crosswell wrote:
> > >
> > > > At the last Joint Techs, we discussed that now that we had IP  
> > > > multicast
> > > > on wired networks all figured out(;-), it was time to start over  
> > > > from
> > > > scratch with IP multicast over WiFi.  The following rough notes
> > > > collected some of the questions to send to WiFi vendors to get  
> > > > their
> > > > responses.  I'm hoping some of you will volunteer to:
> > > >
> > > > a) Review these questions and improve upon them.
> > > > b) Fill in the answers where you know them.
> > > > c) Contact your WiFi vendor(s) and ask them to respond to the  
> > > > questions
> > > > d) Report back to the group with your findings.
> > > >
> > > > Please let me know if you can help with this.
> > > >
> > > > /a
> > > >
> > > > WiFi Multicast
> > > >
> > > > driven by apps: iTunes sharing, zattoo, arootz, IPTV, etc.
> > > >
> > > > Problems:
> > > >
> > > > - flooding to all APs serving an SSID since there's no snooping.
> > > > - multicast sent at broadcast base rate (1 Mbps) to ensure all  
> > > > listeners
> > > > hear it
> > > > - unicast tunnels between lightweight APs and controller replicate
> > > > traffic
> > > >
> > > > ... and some hope or workarounds:
> > > >
> > > > - IPv6 support requires multicast
> > > > - several vendors coming out with IGMP(MLD) snooping to:
> > > >  - distribute between controller and APs
> > > >  - limit traffic to only APs that have receivers associated
> > > > - some vendors using known state of slowest multicast receiver to
> > > > dynamically set the broadcast base rate.
> > > >
> > > > Questionnaire for vendors:
> > > > - please improve on these questions
> > > > - please volunteer to take to your vendor (or potential vendors)  
> > > > and
> > > > report back to the group
> > > >
> > > > - How is multicast sent to AP from the controller?
> > > > - Is multicast flooded to all APs in the SSID or just to AP with
> > > > interest?
> > > > - Is IGMP snooping implemented?  What version(s)?
> > > > - What about IPv6?  IPv6 requires multicast.
> > > > - Is MLD snooping implemented?
> > > > - Can multicast base rate be set higher than the broadcast rate?   
> > > > What
> > > > are the limitations?
> > > > - How does multicast work w/WPA2 security?  Broadcast group key?
> > > > Multiple unicast?
> > > > - How does this work with 802.11n multipath?
> > > > - Is multiple unicast better due to retransmissions at 802.11  
> > > > layer?