All things related to multicast

[Alan Crosswell <>]

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?
>