All things related to multicast

[Bob Riddle <>]

here's my $.02 ... actually probably more like $.002

First, deployment of multicast applications is becoming more prominent 
on university campus.  I've been talking/working with a number of 
universities that are preparing to replace their analog television 
delivery systems with digital video over their network infrastructure 
using multicast. 

My experience/observation is that IGMPv2 does not scale well, when the 
number of interesting multicast channels grows large.  IGMPV3 relieves 
that pressure, by allowing the deployed applications to specify a source 
for the desired multicast channel.  This doesn't imply the need for 
IGMPv2 goes away immediately, as applications like the Access Grid and 
ConferenceXP require multiple sources populate a "single" multicast 
channel.  Such DV "tuners" are in the pipeline to take advantage of SSM.

I'll let real hardware folks respond about switches supporting both 
IGMPv2 and IGMPv3 - all I've learned is that new switches are better 
than old switches (but they have to be the "right" new switches!).



debbie fligor wrote:

> So I've got a feature request in at Apple for IGMPv3 support, and 
> they'd like to know what Mac users wont be able to do if we don't have 
> that support.  I'm not that up on what's out there SSM-wise, can those 
> of you that know what's available now, and what's in the pipeline that 
> is SSM based help me out here?
>
> any other useful points I should make? does having an IGMPv2 speaker 
> using multicast on the same subnet as IGMPv3 speakers cause issues, 
> problems (I vaguely recall that the local switch might back out to v2, 
> but I'm not sure if that's only for the one host or for everything...).
>
> thanks for any help you can provide!
>
>
> > The feature has been requested and I'd be happy to add impact 
> > information if you can give me some kind of idea about how this 
> > University will be impacted. I know that the number of machines will 
> > be difficult to determine, but what features or services will Mac OS 
> > X clients be unable to use should IGMPv3 not be added when the 
> > University starts using it? I read the part about wanting to use the 
> > Mac OS X machine for testing purposes, but more information on how it 
> > affects everyone else will help.

--
Bob Riddle 
()
    Technologist,Internet2
1000 Oakbrook Drive, Suite 300    Ann Arbor, Michigan  48104
Business Phone: 734.913.4257      Fax Number:  734.913.4255

"Math illiteracy affects 7 out of every 5 people"