Generalizing Distributed Computing Environment Global Directory Agent for the Internet
Original Publication Date: 1997-Aug-01
Included in the Prior Art Database: 2005-Apr-01
Hahn, T: AUTHOR [+3]
The strict removal of X.500 as the global directory service needed to resolve typed Distributed Computing Environment (DCE) cell names (locate foreign cells) is described here.
Generalizing Distributed Computing Environment Global
for the Internet
removal of X.500 as the global directory service
needed to resolve typed Distributed Computing Environment (DCE) cell
names (locate foreign cells) is described here.
Directory Agent (GDA) is an application (daemon)
that uses a directory to obtain information on how to contact another
DCE cell. Today, either DNS or X.500 directory can be used. The
invention is to provide the ability to remove the strict dependency
on the X.500 global directory service to resolve DCE cell names, that
is, locate foreign cells. It is true that one could just disable the
X.500 part of the GDA, but this then replaces a restriction on DCE
cell names in that they can only be DNS names. This disclosure
allows any global directory service to be used for cell name
resolution/location and, hence, provides a DCE structure more
acceptable for the Internet and intranets.
cell name resolution functionality of the GDA is
extended with Lightweight Directory Access Protocol (LDAP). This
allows any LDAP accessible directory service to store DCE cell
information, even X.500 servers that additionally communicate via
LDAP. To allow the customer to still run with X.500, i.e., the case
where he does not yet have an LDAP server in his environment, the
X.500 path remains in the GDA to contact X.500 server via the
XDS/XOM interface to the X.500 DUA.
The GDA adds
another path for obtaining cross-cell information,
an LDAP path. Since it is important to preserve the format of a cell
name, it is necessary to define the behavior of resolving a typed
name when both the X.500 and LDAP service paths are started at GDA
start time. When both `typed name' service paths are started, the
resolution will first contact the LDAP path; if unable to resolve the
typed cell name, then the X.500 path will be invoked.
The GDA man page is extended with the new options, -l and -h.
-l This option disables the ability to use LDAP as the
-h addr_LDAP_server Address of the LDAP server in which
information is registered. The value addr_LDAP_server can be
hostbullet:port' where host = the hostname running the LDAP
server. Alternatively, the host can be specified as an IP address in
dotted decimal format port = the port on which the LDAP server is
listening; this is needed if the default port (389) is not used.
This option -h is required when -l is not present.
The gdad command starts the GDA daemon. The Global Directory Agent
(GDA) enables intercell communication, serving as a connection to
other cells through the global naming environment. The default,
gdad, starts all services, that is BIND, X.500, and LDAP.
NOTE: The above can be simplified by removal of the X.500
code path. Currently, it is left in and handled via algorithm for