Global Lambda Integrated Facility

Subject Re: globally unique identifiers for lightpaths?
From Leon Gommans <lgommans@xxxxxxxxxxxxxx>
Date Fri, 07 Dec 2007 09:40:09 +0100


Within our work with Internet2 we discussed the same issue. Essentially your need to refer to a "network session id" that needs to be created in a globally unique way. Each domain may have to take the initiative to create such an identifier. In our discussion with Internet2 we started to called it a Global Resource Identifier (GRI). This identifier essentially allows local domains to assign its resources to this GRI. The information related to local resources can was called a Local Resource Identifier (LRI). Each domain can use its own conventions here. The GRI was essentially build using a domain identifier and some number which each domain is free to choose as long as it is unique and adheres to some format constraints posed by the inter-domain signalling protocol. The random number you mentioned could be one way. One may start to think about domain-id's that some authority will issue and this might need discussion in the GLIF.

Regards .. Leon.

Ronald van der Pol schreef:
On Thu, Dec 06, 2007 at 19:26:29 +0100, Erik-Jan Bos wrote:

Hi Ronald and Dave:

I too support the global naming of lightpath. As one of the "design
criteria" I think it should adhere to the KISS principle as much as

About KISS: you know I fully agree :-)

Hence, I think that the system we come up with should:
* Ensure uniqueness.

Two possibilities, I think:
- central repository
- random number

I prefer the latter.

* Be maintenance free as much as possible (i.e. a name should not change
when one of the characteristics of the lightpath changes).

Do you think the name should remain the same when the lightpath
is re-routed? That rules out an identifier which lists all
the GOLEs or all the local names in the path.

I am not sure. It is convenient to be able to deduct the topology
of a lightpath by looking at the name. If we do not do this, we
really need a good inter-domain monitoring system setup fast.
That system must provide domain and topology info for each lightpath.

* Avoid any notion of a central authority or repository.
* Be able to generate a name on the spot by an organization (i.e.
without going back and forth with one or more peer organizations).

I agree. How about these options:
- generate a random number of X digits
	this will be a unique ID when X is large enough
- take the current time in UTC
	YYYYMMDDHHMMSS, e.g. 20071206200042
	It is highly unlikely that two lightpaths get created at the
	same second

I prefer the latter. I does not need a random number generator program.
Just look at your watch to create this number.

At the moment, my preferred ID would look like this:


GOLE1 and GOLE2 are UN Location codes (


- it is easy to parse because it has a fixed format (22 bytes)
- the number YYYYMMDDHHMMSS ensures uniqueness, especially in combination
  with the two locodes
- it gives the egress and ingress GOLE and thus some kind of topology info