Subject: Re: MASC

From: Pavlin Ivanov Radoslavov <[email-masked]>
Date: Thu, 08 Mar 2001 11:45:59 -0800

[A better place to ask MASC-related questions is
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> Hello,
> What is the difference between the claim-collide and query response in
> MASC??

Just to clarify, MASC uses only the claim-collide mechanism.

> I read the MASC protocl and I didnt understand it??
> will any one please explain it to me.
> thanx you

The spec purpose is more or less to describe the protocol the way it
is, hence it doesn't go into details about alternative solutions.

The main difference between claim-collide and query-response (also
occasionally called request-response) is:

With query-response, if you want to get/use some resource (e.g.,
name or block of addresses), you must request it from a resource
manager. Only after you get a positive acknowledgment from the
manager, then you can go ahead and use the resource. If the manager
is down or not reachable, then the allocation system needs to
consider how to deal with robustness issues instead of keeping you
waiting.

With claim-collide, there is no explicit manager responsible for
the resource allocation. If you want to use some resource, you
shout loudly to everyone "I WANT THAT!". Then you politely wait for
long enough interval of time to make sure that everyone heard you
and that nobody else wanted the same resource. If you hear somebody
else asking for the same resource, then the collision is resolved
unambiguously (e.g. based on timestamp or whatever). If you are
the loser then you must repeat the process by claiming something
else.
After you have waited long enough time without a collision (or if
you are the winner of all collisions), then you pretty confidently
assume that you can use that resource.

Hope that helps,
Pavlin

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From: Ali Boudani <[email-masked]>
Date: Mon, 12 Mar 2001 15:14:28 +0100

Hello,
my question is so simple:
why in the MBGP/PIM-SM/MSDP solution for the problem of multicast we didnt
use the allocation of addresses.
Why BGMP need the use of MASC and the MBGP/PIM-SM/MSDP doesnt need it
thanx

---

From: Pavlin Ivanov Radoslavov <[email-masked]>
Date: Mon, 12 Mar 2001 19:15:46 -0800

> Why BGMP need the use of MASC and the MBGP/PIM-SM/MSDP doesnt need it

MASC is not a MUST for BGMP. It is just one possible solution for
creating the association "mcast address prefix"<->"domain" which is
needed by BGMP. Creating this association can be seen as a
side-effect of the way MASC works. So, you can have BGMP without
MASC if you have some other mechanism to create the above
association.
In PIM-SM for example, the Bootstrap mechanism is the mechanism used
to create the "mcast address prefix"<->RP association, but there are
some other mechanisms as well.
BGMP, similar to all other mcast. routing protocols doesn't not care
about mcast address allocation, because the address allocation is an
application-area related issue.

Similarly, MASC doesn't care about BGMP, and can work without it.

Regards,
Pavlin