TCP/IP Tutorial and Technical Overview - IBM Redbooks

Replicas are stored in a clearinghouse. A clearinghouse is a collection of
directory replicas at a particular server. All directory replicas must be part of a
clearinghouse (although not necessarily the same one).
The Cell Directory Service makes use of the DCE security service. When the
CDS initializes, it must authenticate itself to the DCE security service. This
prevents a fraudulent CDS from participating in the existing cell.
Figure 13-7 shows the directory structure of the CDS namespace. As you can
see, the namespace is organized in a hierarchical manner.
/... Global Root
/..: Local Root
cell-profile lan-profile hostname_ch hosts sec fs subsys
config
hostname
Figure 13-7 DCE: CDS namespace directory structure
junction junction
self profile cds-clerk cds-server
Not all DCE names are stored directly in the DCE directory service. Resource
entries managed by some services, such as the security service (sec) and the
distributed file system (fs), connect into the namespace by means of specialized
CDS entries called junctions. A junction entry contains binding information that
enables a client to connect to a directory server outside of the directory service.
The security namespace is managed by the registry service of the DCE security
component, and the DFS namespace is managed by the file set location
database (FLDB) service of DFS.
Global Directory Service and Agent
The Cell Directory Service is responsible for knowing where resources are within
the cell. However, in a multicell network, each cell is part of a larger hierarchical
namespace, called the global directory namespace. The Global Directory
Service (GDS) enables us to resolve the location of resources in foreign cells.
This is the case when a company wants to connect their cells together or to the
Internet.
Chapter 13. Remote execution and distributed computing 499
dfs
dce
sec
dfs sec