Re: Why MSDP?

["Nagesh Chintada" <nagesh.chintada@alcatel.com>]

Bill,
Isn't it true that MBGP alread is used to announce multicast routes to
these sources? They may not
be host routes but still MBGP is carrying routes for these sources!

Agreed that distributing source routes is a little more work for MBGP, but
IMHO it is far less work
that deploying MSDP protocol. And BGP does indeed handle a large amount of
route changes.....

Besides, relying on an MBGP solution will
1. Make it much easier to deploy PIM-SM interdomain. It becomes as easy (
or so they say)
    as deploying SSM interdomain.
2. Eliminate the extra traffic that is carried by MSDP msgs.
3. Make it that much easier to manage
4. Probably speed up adoption of multicast by ISPs.

I think there are lots of advantages to using MBGP...  can someone explain
what I may be missing here?

Cheers,
Nagesh


Bill Fenner wrote:

> One reason: the timescales for change of active source indications are
> much different than BGP was designed to carry.  BGP wants to carry
> data that doesn't change very often, e.g. see route dampening.  Sources
> can come and go at an arbitrary rate, so the rate of change of the
> information is potentially much higher.
>
>   Bill