Subject: Re: [rrg] belated msg: further description of the recommendation process

From: [email-masked] (Noel Chiappa)
Date: Mon, 14 Dec 2009 16:43:23 -0500 (EST)

> From: Brian E Carpenter <[email-masked]>

    > I have a feeling that the mapping system should be very general in
    > nature, in case the first cut at either the locator or identifier space
    > proves to fall short.

There's an even better reason: to allow migration to new syntax (or new
namespaces) for each type of name. Consider: it's easier to start deployment
of a split in an existing namespace if both new namespaces have the same
syntax as the original one. It minimizes the number of things you have to
change, and also the cost of deployment, which makes it more likely you can
get a positive cost/benefit on the change - without which the deployment will
never happen. Once the split is more-or-less complete, then you can start to
think about changing the syntax, or having a new (parallel in function)
namespace.

Or, at least, that's my theory - and I'm sticking to it! :-)

    > Also I feel it should support hierarchy, even if we don't need a
    > hierarchy from the start.

Hierarchy in the names in the namespaces, or a hierarchy _of_ namespaces?
Sorry, wasn't quite clear from your brief comment.

	Noel

---

From: Brian E Carpenter <[email-masked]>
Date: Tue, 15 Dec 2009 15:58:42 +1300

> think about changing the syntax, or having a new (parallel in function)

Agreed.

> Sorry, wasn't quite clear from your brief comment.

I was thinking about a hierarchy of namespaces, but in fact we probably
need the generality to support hierarchical names too. I don't think that
needs to make the simple case inefficient. Just make a couple of the basic
data definitions recursive, and you've got both hierarchies.

   Brian

---

From: Lixia Zhang <[email-masked]>
Date: Mon, 14 Dec 2009 22:30:51 -0800

On Dec 14, 2009, at 6:58 PM, Brian E Carpenter wrote:
> ......

a clarification question: wonder what is the "name space" referred to  
in the above?

Lixia

---

From: Brian E Carpenter <[email-masked]>
Date: Wed, 16 Dec 2009 11:17:21 +1300

Several replies in one message:

On 2009-12-15 19:30, Lixia Zhang wrote:
> a clarification question: wonder what is the "name space" referred to in
> the above?

I was interpreting Noel to mean what we colloquially call an "address space",
whether identifier-addresses or locator-addresses. But namespace is
an abstract concept. I have a little trouble with the IEN19 definition,
since it clearly uses "name" for what we now call identifier and
"address" for what we now call locator.

On 2009-12-15 22:52, Tony Li wrote:

> Our recommendation is focused on providing an alternative routing architecture.  A mapping system is a fine component, but would not seem to provide a credible architecture by itself.

I agree, but what it means is that a routing proposal that requires a
mapping solution needs to specify it. I'm arguing that it needs to specify
it as a separable component.

On 2009-12-16 03:55, Noel Chiappa wrote:

>     > I was thinking about a hierarchy of namespaces
> 
> To help me understand how this would work, could you give an example?

http://www.cs.auckland.ac.nz/~brian/layers.pdf

> 
>     > Just make a couple of the basic data definitions recursive, and you've
>     > got both hierarchies.
> 
> And an example of this too...

Oh, I was just thinking in BNF terms, or defining the namespaces
like DNS does. Not intended to be a profound statement.

But it does get you to variable length addresses,
locator = prefix suffix [locator]
or something like that.

   Brian