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Directory Consultants

This page contains brief details on Directory consultants.


Andersen's L-Service



Andersen's L-Service is a one-man consultancy owned by Erik Andersen, the ITU-T Rapporteur on Directories. The company is located in Denmark, but operates internationally.
Besides providing general data communications consultancy, the company has more than 20 years of Directory experience.

Erik Andersen may be contacted by clicking here.

It is not a straightforward exercise to establish a well-functioning directory. The success and usefulness of a directory are dependent on the organisation making all the right choices.

Assistance is provided in the following areas:

  • X.500 education/seminars - One or two days seminar available customised for the particular situation. It may include an introduction to ASN.1
  • Identification of requirements - Before procuring a directory system, the requirements on the system must be determined. The requirement study should include:
    • what the initial load should be;
    • identification of the different user groups;
    • an estimate of the number of users in each user group;
    • an analysis of the requirements of different users groups for information access;
    • response time requirements;
    • sizing;
    • integration with other services;
    • Requirement on user interface.
  • Naming and information structure
    • what information items the directory shall be hold (names of persons, telephone numbers, e-mail addresses, employee numbers, etc.);
    • how such information items (attributes) should be organised in directory entries;
    • what the relationship among different entry types shall be;
    • the naming structure based on the entry relationship and general naming principles.
  • Procurement specification - what should be considered in a procurement specification and what should be vendor selection criteria:
    • Flexible schema and name structure support
    • Access control support
    • Administrative tools, including access control customisation
    • Tools for import/export of information
    • Back-up and recovery features
    • Service and maintenance
  • Operational architecture:
    • Distribution across directory servers;
    • The requirement for replication shadowing.
  • Data management strategy:
    • scope of initial load
    • Update strategies
    • Quality of data (accuracy, completeness and timeliness
    • Distribution of administrative roles
    • Use feed back (reporting mechanism)


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