All things related to multicast

[Bill Nickless <>]

At 01:29 PM 5/13/2002 -0700, David Meyer wrote:
> If ASM is going away, should we give up on MSDP (from the
> standards perspective)? I'm struggling with this problem right
> now. If we give up, what should we do with (i). what's deployed,
> and (ii). the current spec?
>
> As always, opinions and advice greatly appreciated.
>
> Dave

My opinion:

 - To solve the long-term problem, draft a new multicast service
   model to obsolete RFC-1112.  I might know someone who's taken
   a stab at that already.  :-)

   Include in that service model the reality that IPv4 interdomain
   multicast routing uses (S,G)-rooted distribution trees, and that
   the interdomain internetwork must know of all (potentially) active
   sources and interested receivers before the (S,G)-rooted
   distribution tree is created and packets can flow.

   SSM meets that criteria by requiring receivers to explicitly name
   potential sources.

   ASM meets that criteria by the network spreading knowledge of active
   sources through MSDP.

   (This is an MBONED function, I think.)

 - In the final MSDP RFC, an implementation MUST accept encapsulated
   data from its peers.  An implementation SHOULD NOT transit that
   traffic to its peers; instead, it should remove the encapsulated
   data and send zero as the data length.

   Specifically, in draft -13 section 16.2.1 the outgoing IPv4
   Source-Active TLV Length y SHOULD be zero, and encapsulated
   data SHOULD NOT follow.

   (That's my bow to the reality of existing implementations that
   think they must encapsulate data outbound.)

My $0.02.

===
Bill Nickless    http://www.mcs.anl.gov/people/nickless      +1 630 252 7390
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