[ih] Why did location/identity separation not happen? (Was: Internet without entrenched factions?)

[Dave Crocker]

On 5/20/2026 5:10 PM, vinton cerf wrote:
> On Wed, May 20, 2026 at 4:22 PM Dave Crocker via Internet-history 
> <internet-history at elists.isoc.org> wrote:
>
>     End-point has always been an intuitively appealing, but IMO
>     problematic,
>     term.  Is it an interface?  A host?  An application? (And which
>     layer of
>     an application service?  I always thought of an email address as
>     defining an endpoint.  Until I dealt with EDI over email, where the
>     receiving email inbox was only an intermediary, and an EDI identifier
>     indicated that ultimate end-point..)
>
> well, could one argue the endpoint at the IP layer gets you to the 
> host, TCP gets you to a process and after that it is an application 
> layer question?

Exactly.  So, using a label that is ambiguous means it needs a 
qualifier.  IP endpoint:  IP Address.  TCP endpoint: Port # (+ IP). 
Application endpoint (...?)


>     So... my home network is dual-homed.  To two, independent ISPs.
>     Through
>     NATs.  I don't have an A/S.  I am not aware of any capability,
>     deployed
>     as scale, that deals with that model usefully.
>
> A colleague applied for an AS to make his dual homing work

Should be fun, trying to make that work at scale.  I'm sure routing 
tables would love that.  Never-mind end users...

So, I don't think the answer is for every home network to be an A/S.  I 
think the answer has to be to make the application transport-agile.  So 
it can use different transport connections (and different network 
attachments and different ISPs) in a seamless fashion.

The issue doesn't show up much, so far, because for most people the 
Internet experience is too reliable.

The cases where it isn't or where the user is mobile but not on a cell 
service (which handle the access transitions within its unified 
infrastructure) don't happen often enough to create market pressure (or 
maybe even market opportunity) to motivate change.



>     > If the notion of destination had been framed as "ID of
>     > destination host" the other routing choice might have been more
>     obvious.
>
>     When someone makes a point like this, I always ask why domain name
>     does
>     not or should not serve that role?
>
> it doesn't in the sense that the routing isn't done on that identifier 
> in the case of the Internet.
> The routing is done on the basis of IP address.

Sure.  But this thread is about location/identity constructs and my 
question is why an additional 'identity' construct is needed at the 
lower layers?  Why aren't  domain name (and associated DNS records) 
sufficient?

d/

-- 
Dave Crocker

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