Using X.500 to determine presentationAddresses

Peter Yee <> Fri, 07 May 1993 09:58 UTC

Received: from by IETF.CNRI.Reston.VA.US id aa01159; 7 May 93 5:58 EDT
Received: from CNRI.RESTON.VA.US by IETF.CNRI.Reston.VA.US id aa01155; 7 May 93 5:58 EDT
Received: from by CNRI.Reston.VA.US id aa03455; 7 May 93 5:58 EDT
Received: from by with local SMTP id <>; Thu, 6 May 1993 07:57:55 +0100
Received: from by with Internet SMTP id <>; Thu, 6 May 1993 07:57:48 +0100
Received: from by with SMTP (PP); Wed, 5 May 1993 23:57:39 -0700
Subject: Using X.500 to determine presentationAddresses
Date: Wed, 05 May 1993 23:57:37 -0700
Sender: ietf-archive-request@IETF.CNRI.Reston.VA.US
From: Peter Yee <>
Message-ID: <9305070558.aa03455@CNRI.Reston.VA.US>

I was involved, the other day, in a lively discussion on how we could use our
X.500 directory systems to look up presentation addresses for various services
and hosts.  I'm not talking about a small number of machines, but potentially
thousands.  The questions boiled down to: "How do you name a host and service
in the OSI world (akin to a DNS hostname and a TCP/UDP service name/port)?",
and given that you have such a name, "what is the best way to use X.500 to
retrieve the corresponding presentation address?"  Has anyone given thought
to how this should be done?

I'm aware that the ISODE contains an implementation of DASE which allows one
to look up a presentation address given a user-friendly name (UFN) and an
application context.  However, if, for example, I wanted to put all of the
machines at NASA Ames Research Center into the directory and use DASE to do
lookups, I would end up with a few thousand additional entries under the DIT
location US, NASA, ARC.  This is where my people entries are.  And this is
where one might logically expect to find my machine entries.  Clumping them
together, though, means that search performance for both people lookups and
service lookups goes down.  And if I'm not using DASE, I've no idea where I
might need to search (particularly since there is no standardized naming
scheme for OSI end-systems).

Well, has anyone got some ideas on this one.  I'd love to hear them.  Anything.

My thanks in advance.

							-Peter Yee