RE: Some Comments on ID/Loc Separation Proposals

["marcelo bagnulo" <mbagnulo@ing.uc3m.es>]

> >    Endpoint
>
> >            refers to "the fundamental entity of and end-end
> >            communication" [EID]. It is an end-system that participates
> >            in an association. Endpoints are distinguished from
> >            intermediate, infrastructure nodes and from hosts.
>
> An endpoint is an end-system but not a host: I think this isn't all
> that clear.
>
> Personally, I prefer to talk about hosts, as this is a well-known
> concept.

I guess this is exactly the problem :-)
People has a pre defined concept about what a host is, so they assume
properties about it.
That is why it is good to use a different term such as endpoint, that can be
defined properly



> The fact that there is some ambiguity because hosts can be
> clustered and virtualized also isn't a huge surprise to most people,
> and can be spelled out for good measure.

I guess that something about the relation between a host and an endpoint can
be inlcuded.

>
> If you want to stick to "endpoints" you should say whether an endpoint
> is host that may or may not be virtual, a transport protocol or a
> process. This has pretty serious consequences for the number of
> identifiers that is necessary and some other stuff as well. For
> instance, certain types of communication may be handled by more than a
> single processes. When identifiers are tied to processes this makes
> referral very complex.
>
> >    Identifier
>
> >            refers to a unique label for an endpoint.
>
> Hm, maybe this is just my English but to me it is unclear whether you
> mean the identifier <-> endpoint relationship is 1-to-1, 1-to-n or
> n-to-1, only that it isn't n-to-m.
>

good point

i would say that the relation is n-to-1

but this should be defined and clarified in the text

> I think "an identifier identifies a specific endpoint" is enough.
>

I think we need more than this, in order to be clear. The proposed text with
a modification to explicitly define the n-to-1 relation should be good
enough IMHO

> >            The label is used
> >            simply for distinguishing one endpoint from another.
> >            Because a locator is usually globally unique, it might be
> >            able to serve as an identifier. However this use will often
> >            suffer administrative and referential limitations as a
> >            global identifier for mobile endpoints. This is exemplified
> >            by the current problems experienced with the dual role of
> >            IP Addresses.
>
> This is too much text and largely not relevant for defining
> "identifier". The only additional remark that's necessary is that an
> identifier is independent of an endpoint's attachment to the network
> ("location").

I guess that this is not what Dave is trying to say...
the locator can be used as an identifier, since it is unique, but its usage
as an identifier presents some limitations

Regards. marcelo

>
> > As with others, I do not think it is useful to have ID refer to an
> > interface.  Stack, endpoint or process all seem more helpful.
>
> Absolutely. While multi6 is about site multihoming and not host
> multihoming, it would be a mistake only allow jumping locators when
> those locators are tied to the same interface.
>
> "Endpoint" is usable, but "stack" isn't a very good word as it will
> probably confuse people who haven't followed what has happened in the
> NSRG and identifying processes is too granular and dynamic, IMO.
>
>