Re: [mpls] IANA Considerations was Re: AD review of draft-ietf-mpls-ldp-multi-topology

["Adrian Farrel" <[e-mail]>]

Hi Tom,

Repeating history is not always the right way to decide what the right thing to
do is.

> > Why do you say that this updates RFC 4379? Is it your belief that an
> > implementation of RFC 4379 will not be complete/conformant without
> > these extensions? Or are you just defining extensions which an
> > implementation in an MPLS-MT environment will need to support?
> >
> > I note that you (in my view, correctly) do not say that this document
> > updates RFC 5036, yet it defines extensions to LDP in a similar way.
> 
> I am not sure I follow this logic; RFC6426 adds TLVs and sub-TLVs and is
> recorded as updating RFC4379.
> 
> That RFC also updates the "Pseudowire Associated Channel Types" registry
> but is not recorded as updating the RFC for that registry.
> 
> So I think that this I-D is following a pre-established path.

My logic is that if this document updates 4379, then it also updates 5036
because in both cases, this I-D adds TLVs to the protocols defined in those
RFCs.

But the trend of usage of "updates" is not the weaker "adds some protocol
extensions", but the stronger "adds to the core function set".

Thus, a reasonable view is that if you were republishing the base protocol spec
tomorrow, would you fold the new work into that specification? If so use
"updates". If not, do not.

I am still open to the argument that this document *does* update 4379, but I
don't see it. I think you would only use MT LSP Ping in MT deployments (just as
you would only use MT LDP in such deployments) and core implementations of MPLS
might choose to support neither.

Cheers,
Adrian