Global Lambda Integrated Facility

Subject Terminology discussion
From Freek Dijkstra <fdijkstr@xxxxxxxxxxxxxx>
Date Fri, 30 Sep 2005 21:23:03 +0200

Just yet, there was a plenary discussion on some basic terminology for GLIF:

* GLIF physical resource:
  - Lambda
  - GLIF Open Lightpath Exchange
* Physical resource owners
* LightPaths (and services)

Allow me to stir up the discussion a bit more, but this time on the list instead of plenary.

I think it might not have been clear that (in my humble opinion) this is a not a technical defination. For technical definiation, we really need more detail.

Let's give an example about "resource owners". It can mean "legal owner", "economic owner", "administrator", "operator". (e.g. IEEAF may pay -economic owner- for a Global Crossing -legal owner- circuit, administrated by SURFnet, and operated by SARA).

However, this is not so convienant for our lunch-time chit-chat (or , unless you're really a TMN geek, so we need some more basic terminology, which we should be able to explain to our mother (unless you're Lars Fischer from NorduNet, since he just confessed his mom DOES have a telecom-background). Such a basic terminology should be terminology independant, or we end up changing it every few year. If you're really interested in that, please read ITU G.805, or <shameless plug>watch our work on network description languages</shameless plug>.

Basically, there are tree technicall elements, which have been defined a lot of time in different protocol.

* Central locations
* Connection between those locations
* An end-to-end connection

Locations are hops or exchanges, and may be complex, have service, or even be distributed if that's what we want.
However, we don't define the details here yet. Just the basic terms.
A connection is a basic, transport capacity between two locations.
These basic connections can be divided into channels, to allow multiple datastreams on the same connections, and then concatenating those channels (or connections) into a tandem which results in an end-to-end connection for use by end-users or applications.

In Graph theory, this is respectively:
vertices, edges and path

In ITU G.805 it's called:
connection point (CP), link connection (LC) and network connection (NC)

In telecommunications, it's called:
exchanges (or switches), trunks and circuits

In IP, it's called:
hop, a Layer 2 link (or link-local connection), connections

In my day-to-day talk, I call this:
transport exchange, link and path

Someone else may call it:
open optical exchange, transport service and e2e connection

Well, and in GLIF it's now (propesedly) called:
GLIF Open LightPath Exchange (GOLE), lambda and LightPath

Yes, I do think these particular words sucks. It's loosy. (I would obviously prefer my words), but at least it avoids confusion, so I'm fine using these words in this community.

Freek Dijkstra