All things related to multicast

["Marshall Eubanks" <>]

On Mon, 13 May 2002 22:34:28 -0700 (PDT)
 Hans Kuhn 
<>
 wrote:
> Marshall,
> 
> For your SSM sources I suggest you use the 232 space for
> several reasons:
> 
> * readily identifiable at a glance as SSM vis a vis the
> address (i.e. useful for debugging)
> 
> * most apps (including mim) rely on the presence of a 232
> address to recognize an SSM session

I figured that this was what was going on with mim last week.
We had the command line configured for SSM, and it died.
Since there is no real means for routing protocol discovery, I
suspect as a practical matter that a lot of applications will use this
as a short cut.

I must admit that as a practical matter, I am dubious about the effacy of just
treating ASM sessions as if they were SSM. The two were deliberately intended
not to interoperate at the group level, and it seems like a kludge to treat 
them
as if they were.

Marshall

> 
> * 232/8 is a nearly inexhaustable supply of addresses.
> Remember that SSM uses S,G for each session. Even if you
> only have a /24 of host addresses you have 
> 
>   253 host addresses * 24 bits of SSM addresses
> 
> worth of addresses for SSM sources. I challenge you to use
> that up! (using a Digital Fountain box is cheating ;)
> 
> Hans
> 
> -- 
> Hans Kuhn, Academic User Services          office (541) 346-1714
> University of Oregon, 237 CC               fax    (541) 346-4397
> 
> Key fingerprint =  1E BC 32 03 AC E9 82 6C  44 4A CD 63 BB 2D 51 89
> 
> On Mon, 13 May 2002, Marshall Eubanks wrote:
> 
> :    On Mon, 13 May 2002 16:48:33 -0700
> :     John Zwiebel 
> <>
>  wrote:
> :    > 
> :    
> :    John et al.;
> :    
> :       Before the recent Minneapolis IETF, I was strongly in favor of
> :    removing encapsulation from the MSDP draft. During the meeting, 
> however,
> I
> :    changed my mind. What convinced me was the following argument :
> :    
> :    Multicast only has a limited amount of political capital from
> application
> :    developers, router vendors, etc. This limited amount of mindshare 
> should
> applied
> :    to issues, such as SSM, that are likely to advance the technology.
> Trying to
> :    "fix" MSDP is a waste of poltical capital.
> :    
> :    So, my feeling is, document MSDP as it stands now, encapsulation and
> all, put
> :    the draft out (as informational ?), and move on.
> :    
> :    Marshall
> :    
> :    P.S. We want to start sourcing SSM video soon. A query - which would be
> better:
> :    to declare part of our GLOP space to be SSM, or to use the SSM address
> range ?
> :    Which would be easier to use mim with ?
> :    
> <snip>
>