RFC 2120 (rfc2120) - Page 3 of 14

Managing the X

RFC 2120         Managing the X.500 Root Naming Context       March 1997


2     Migration Plan

   The NameFLOW-Paradise service is now migrating to X.500 Standard
   [X.500 93] conforming products, and it is essential to replace the
   Quipu replication protocol with the 1993 shadowing and operational
   binding protocols, but without losing the performance improvement
   that has been gained for one-level Searches.

   It is still the intention of the NameFLOW-Paradise service to have
   one master root DSA. This root DSA will not support user Directory
   operations via the LDAP, the DAP or the DSP, but each country (first
   level) DSA will be able to shadow the root context from this root
   DSA, using the DISP. Each first level DSA then only needs to have one
   bi-lateral agreement, between itself and the root DSA. This agreement
   will ensure that the first level DSA keeps the root DSA up to date
   with its country level information, and in turn, that the root DSA
   keeps the first level DSA up to date with the complete root naming
   context. When a new first level DSA comes on line, it only needs to
   establish a bi-lateral agreement with the root DSA, in order to
   obtain the complete root context.

   This is a much easier configuration to manage than simply a set of
   first level DSAs without a root DSA, as suggested in the ISO X.500
   Standard. In the X.500 Standard case each first level DSA must have
   bi-lateral agreements with all of the other first level DSAs. When a
   new first level DSA comes on line, it must establish agreements with
   all the existing first level DSAs. As the number of first level DSAs
   grows, the process becomes unmanageable.

   However, it is also important to increase the amount of information
   that is held about every country entry, so that a one-level Search
   operation can be performed in each first level DSA, without it
   needing to chain or refer the operation to all the other first level
   DSAs (as is currently the case with a X.500 Standard conforming
   system.)

3     Technical Solutions

   3.1 The solution at first appears to be relatively straight forward,
   and involves two steps. Firstly, create a root DSA, and establish
   hierarchical operational bindings using the DOP, between it and each
   master first level DSA. Secondly, each master first level DSA enters
   into a shadowing agreement with the root DSA, to shadow the enlarged
   root context information. In this way each first level DSA is then
   capable of independently performing List and one-level Search
   operations, and name resolving to all other first level DSAs.





Chadwick                      Experimental