Re: [Inip-discuss] Domain Names

[Lyman Chapin <[e-mail]>]

On Jan 14, 2016, at 4:17 AM, Olaf Kolkman wrote:

> On 13 Jan 2016, at 19:04, Lyman Chapin wrote:
> 
>> It is! But several people have pointed out that although it may be useful, it isn't satisfying. In the math/graph realm we have the domain name space and we talk about trees, subtrees, and vertices. In the DNS realm we have zones, subzones, and zonefiles and we talk about delegation, name servers, and resource records (among other things). It's useful to discuss the name space separately from the resolution protocols, but from an engineering standpoint the usefulness level is much higher if we also know how specific systems (like the DNS) use the name space - the correspondence or mapping, if you will, between the math/graph realm and the DNS (as a system of protocols) realm.
> 
> Hmm… but I thought we were discussing the syntax of the name-space. It seems that we then arrive at 3 things that all hook together: syntax, namespace, and resolution protocol.

A domain name that identifies a point within the domain name space has a syntax, but the name space itself does not. Syntax is a set of rules that govern the structure of (in this case) domain names - the composition of labels, and how they may be ordered. The domain name space is just a labelled directed rooted tree, a math/graph construct that doesn't have (or need) a syntax. (I apologize for the way in which this sounds "preachy" - I'm just trying to be as precise as possible in the way in which these terms are used.)

> 
> The Internet DNS namespace is specifically defined through the resolution system starting at the IANA root. To first approximation it is the hints file used at the resolver that defines the name-space.

The domain name space is explicitly (going back to RFC 1034) not defined by the DNS resolution system. If it's useful to do so, we can define the "Internet DNS namespace" to be the domain name space overlaid with the semantics expected by the resolution system (servers and resolvers). But that would assume an answer to at least one of the questions we're still discussing: "if it is resolved by something other than the DNS, is it a domain name?"

> 
> I lost track of the question that we are trying to answer? Ed, is there some underlying thing you want to arrive at? Do you want to arrive at a precise definition of Domain names or do you want to solve the confusion that arrives from identifiers that look like domain names?

I believe that "precise definition" will help us remove that confusion - but if I'm just adding to it, you (or Ed, or anyone else) should feel free to tell me -

- Lyman