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From: S.Kille@CS.UCL.AC.UK (Steve Kille)
Newsgroups: comp.protocols.iso
Subject: Re: Encoding RFC 1006 addresses in X.500
Message-ID: <1661.632658389@UK.AC.UCL.CS>
Date: 18 Jan 90 10:26:29 GMT
References: <27011.632598190@cheetah.nyser.net>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 44

Nothing like NSAPs to produce a lot of messages!

On the choice of Prefix for use of RFC-1006 over Internet TCP/IP.
My note proposed TELEX AFI (54) + UCL Telex + 03 .  Rob suggests
47 (I assume that this is ICD AFI??).

It doesn't matter much which number is chosen.  There is no technical reason to
change, althogh there may be some emotive ones.  

A change would not be that big a deal if it was done soon.  It would cause
MTR and the ISODE crew a fair  amount of short term grief, and it would
break some directory pilot activities for a bit.  I would certainly
recommend against changing if it can be avoided.   

If it will help, I am very happy to delgate the .....03 namespace to an
appropriate body.   If you'd like it to be more formal, I'm sure that Prof.
Kirstein will be happy to write this on UCL headed notepaper to an
appropriate Internet person or body.  

There are a number of reasons why the TELEX (54) namespace makes sense:

- My encoding needs quite a bit of space, mainly to make it easy to
  handle and to proivde sufficienct flexibility.   The Telex form
  gives you a lot of space easily.  It might be hard to argue for
  a large enough chunk of the 47 namespace.

- This is a non-(OSI)-standard use of NSAPs.  Using a suitably bizarre
  part of the NSAP-space will emphasise this.   It can be easily dropped
  out at a later stage.

- You do not want real NS systems to get confused by this.  Separating these
  "special" addresses as far away from real NS addresses (which I assume is
  mainly what will be under 47) is likely to promote robustness.  This
  was the orignal aside which I made, and did not explain properly then 
  (apologies).   Of course, real NSAPs could use the Telex Namespace, but
  this is not going to be a common option. 

I hope that this helps you to sort things out


Steve