All things related to multicast

[Leonard Giuliano <>]

On Thu, 20 Dec 2012, Bill Owens wrote:

-) On Mon, Dec 17, 2012 at 01:57:14PM -0800, Leonard Giuliano wrote:
-) > 
-) > Dan, Bill, et al- interdomain multicast ain't dead yet!
-) > 
-) > The previous efforts from 12-14 years ago to get everyone in the world 
to 
-) > enable mcast natively have beyond a doubt failed miserably.  Multicast 
has 
-) > a number of problems, and I'm sure the folks on these mailing lists can 
-) > each come up with plenty of their own favorites.  But the biggest 
problem 
-) > has always been that multicast is an all-or-nothing solution, and 
getting 
-) > every layer 3 hop, every router and firewall on the Internet to just 
turn 
-) > on a few new protocols was simply something that wasn't going to happen. 
 
-) > However AMT solves that problem.  With AMT, multicast works gloriously 
in 
-) > natively-enabled pockets of the Internet, but also can be received in 
the 
-) > other 98% of the Internet that doesn't support multicast.
-) 
-) Okay - so the use case is native intradomain multicast, with 
-) interdomain provided by AMT? Works for me - I get to drop native 
-) interdomain multicast support from my network, and the user doesn't 
-) know either way (so no complaints ;)
-) 

I would say the use case is Internet Multicast that actually works.  That 
is, if you want to transport it efficiently across your network, deploy 
natively.  If you aren't native, you will simply get tunneled over.  
Either way, the source and receivers are happy.

There are lots of other use cases- tunneling over the last mile or 
wherever legacy gear exists that doesn't support mcast, etc.  But the 
general use case description for all of these is the same- multicast that 
actually works everywhere.