1. Overview Directory Survey danny.van-roosbroek@eurocontrol.int
AFSG/PG
WGN04-WP30-Annex
Overview
Directory Survey
New Orleans - 15/16 Nov 2004

2. Introduction AMHS expects support of X.500 Directory DAP
Doc 9705 specifies ATN Specific Dir Information
EUR-AMHS and SPACE originally mandated Directory
Some ATSPs interest in RFC’s LDAP - for cost effectiveness
Do products support ATN Specific information over DAP? - over LDAP? over WEB?
So - A limited survey to discover the reality …..

3. Rationale & Problem Statement
X.500 DAP is regarded as ‘expensive’
LDAP/WEB are regarded as ‘cost effective’ - free
But ATN Directory specifies special ATN information
Do DAP/LDAP/WEB products support ATN information?
Will costs increase for ATN Information support?

4. ATN Directory User Types
Users
Gateways
Servers
X.500 Directory
Administrator
XML-HTTP<>DAP
WEB Gate
X.520/
521
ATN
General Users
LDAP<>DAP
LDAP Gate
X.402
X.509
AMHS User
DAP
DAP
AMHS UA or MTA
‘Online’
Group 1and 2 Systems
(Based on Directory Product Survey)
LDAP
Server
LDAP
LDAP User
Group 3 Systems

5. Schema Principles Schema Definitions DIT Elements Object Classes
Attribute Types
Attribute Syntaxes
DIT Structure
DIT
Entries
Attributes
Values
rules for
uses
belongs to
rules for
uses
belongs to
rules for
belongs to
uses
rules for

6. Schema Definition - 1 Object Class Attribute Type
Lists Attribute Types in an Entry
Defined by name + Object Identifier + List
No software to implement in DUAs/DSAs
Attribute Type
Names an Attribute Type
Defined by Name + Object Identifier + Attribute Syntax
No problems - only user configuration required

7. Schema Definition - 2 Attribute Syntax (e.g. Integer, string …)
Describes the encoding of an Attribute Value on the communications line
Defined by Object Identifier + Name + ASN.1 specification of value
Suppliers must write software
Specifying new Attribute Syntaxes costs money

8. ATN Schema Additions ATN adds several new Object Classes - no problem
ATN adds several new Attribute Types using existing (Standard Syntaxes) - no problem
ATN adds two new attributes with new syntaxes
Global-Domain-Identifier - now resolved!
MTCU-Characteristics - a complex syntax - needs review!

9. Research - How? Suppliers questionnaire:
What schema elements are available as standard for DAP, LDAP (and WEB) access?
Do tools exist for configuration of new schema elements?
What schema elements need new software?

10. The Surveyed Suppliers
ISODE - NEXOR - Data Connections - HP - ATOS-Origin
SUN - Critical Path (ICL) - Bull - CDC - Computer Associates - Fujitsu - IBM - ISOCOR - Maxware - Microsoft - NCR - Siemens - Sun - Syntegra - Tandem - Unisys …...
COMSOFT - Thales - Avitech - Copperchase - Boldon James - Global Weather

11. Results - Analysis One supplier supports the ATN Extensions in DAP
No suppliers support ATN Extensions in LDAP
ATN extensions inevitably incur extra cost
ICAO could consider re-defining the ‘expensive’ attributes
WEB (HTTP) needs no new syntax definition (but requires a WEB site gateway

12. Recommendations - 1
User Communities should avoid defining Attribute Types using complex, non-standard syntaxes
ICAO WGN should re-define the MTCU-Characteristics Attribute Type (the Global Domain Attribute has now been re-defined)
ICAO WGN should consider whether LDAP is required
ICAO must specify the ATN-specific schema elements in Backus Naur Form if LDAP is to be used
XML should be avoided
No further specification is required for HTTP access

13. Recommendations - 2 Possible Architecture
WEB Browser Access
WEB
GATE
General Users
LDAP Access
LDAP
GATE
ATN-Directory
DIB
AMHS Users
Direct
DAP
Access
DAP Access
MTA & UA Processes +
Dir Administrators
(Based on Directory Product Survey)

14. Thank You