Subject: [lisp] Deployment: Map Resolvers

From: "Joel M. Halpern" <[email-masked]>
Date: Wed, 13 Oct 2010 13:07:27 -0400

Again, speaking just as a participant...

The document says that Map Resolvers would be deployed by ISPs.
I had somehow gotten the impression that Map Resovlers would be deployed 
by EID assignment authorities, who would also be running the BGP routers 
taht participate in the ALT infrastructure.

In particular, if Map Resolvers are run by ISPs that implies some 
coupling between ISP support and end customer usage of LISP, which seems 
to be something we had been avoiding.

Yours,
Joel

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From: Vince Fuller <[email-masked]>
Date: Wed, 13 Oct 2010 11:30:52 -0700

> to be something we had been avoiding.

Map Resolvers don't have to be run by ISPs but it makes sense for an ISP
to offer such a service to its customers. Since an ISP is topologically
closest to its own customers, this makes sense for performance reasons.

We do expect for Map Servers to be operated by Mapping Service Providers
(MSPs) and that the EID assignment authorities will be MSPs. MSPs can
certainly operate Map Resolvers as well though sites using them may be
more topologically distant from an MSP than from its own ISP.

Does this make sense?

	--Vince

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From: "Joel M. Halpern" <[email-masked]>
Date: Wed, 13 Oct 2010 14:40:21 -0400

That makes sense.  This seems to be a case where it is important to 
differentiate between necessity and capability.

Anyone who can get the necessary business relationship with the ALT can, 
in principle, run a Map Resolver.
Is it the case that any client can use any Map resolver that it has a 
suitable business relationship with?  (Could there even be "open" 
resolvers?)

However, any LISP site needs to be able to reliably get to some Map 
Resolver.  It seems to me that this implies that MSPs need to run Map 
Resolvers, so that clients can use them if they do not have a resolver 
that they think will work better.

Yours,
Joel

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From: Vince Fuller <[email-masked]>
Date: Wed, 13 Oct 2010 11:48:09 -0700

On Wed, Oct 13, 2010 at 02:40:21PM -0400, Joel M. Halpern wrote:
> in principle, run a Map Resolver. Is it the case that any client can use
> any Map resolver that it has a suitable business relationship with?
> (Could there even be "open" resolvers?)

Yes, eys, and (yes). In fact, all of the Map Resolvers on the LISP pilot
network could currently be described as "open" as they don't enforce any
access controls. Map Servers, on the other hand, must be explicitly
configured to accept Map Registrations from authorizes ETRs.

> that they think will work better.

Sure, that makes sense. I'd encourage the authors of the LISP Deployment
document keep this discussion mind...

	--Vince