Re: Some comments on the recent discussion on sm-interest@cs.ucl.ac.uk

[Jon Crowcroft <J.Crowcroft@cs.ucl.ac.uk>]

In message <199905171643.JAA08400@squirrel.cisco.com>, David Meyer typed:

david, this is really helpful - many thanks


 >>        (i).    There is a growing amount of PIM-SM and MSDP
absolutely ,and we should help this _as well as_ thinking about longer
term.
 
 >>        (ii).   Bidirectional trees can be done as a delta to PIM-SM,
 
yes...

 >>
 >>        (iii).  Extended addresses for more scalable address
 >>                allocation could also be done as a future delta to
 >>                PIM-SM and/or BGMP...and as the longer term
 >>                replacement for MSDP. 
 
yes....sm could be part of future pim....

 >>        (iv).   One of the issues that has come up on this list and
 >>                elsewhere is the need to perhaps define a small number
 >>                of group types. I guess the discussion needs to be
 >>                about whether we understand the differences well
 >>                enough at this point to do that or whether fragmenting
 >>                the address space is a bad idea. BTW, when we talk
 >>                about "group types", I take it to mean thinks like:

 >>                o Generic multicast groups
 >>
 >>                o Bidirectional groups

 >>                o Restricted source groups (as originally suggested by 
 >>                  EXPRESS, i.e, the ability for "Disney channel" to
 >>                  get a group that routing will only allow a certain
 >>                  source to send on, etc.)    

additional to this is that certain applications may need a mixture -
e.g. RM protocols that use one tree for data and another for
retransmits (and multiple source RM protocols that use 1 for data and
multiple trees for retransmits rooted at retransmit servers - could
work VERY nicely with PGM...)

 >>                For the most part all of these types of groups can be
 >>                supported with currently deployed  protocols.  
work, yes; efficient, maybe not.


 >>        (v).    Remaining work

 >>                o Finish the work on Bidirectional deltas to make that
 >>                  a near term option 

agree
 >>                o Define extended address delta to PIM and any other
 >>                  existing protocols 
 
agree 

 >>                o Decide and define what to do about multicast group
 >>                  types (EXPRESS and others)
 
yes....but do you think this should happen in the PIM WG? Or should we
have anothe working group so that we dont have to re-charter pim -
maybe call it PIMng?

 >>                o Continue with the current and ongoing security work 

absolutely
 >>                o Continue with the currrent and ongoing management
 >>                  work
 
of course.....

 cheers

   jon