CORBA 2.3.3 Programmer's Guide for C++ (NonStop CORBA 2.3.3+)

Figure A-2 expands the view of NonStop CORBA to include several more important concepts. Stubs and skeletons exist for each object type. The
ORBs must use one or more transport protocol mechanisms or transport types.
If the TCP/IP transport protocol is used, the Bootstrap Service Daemon (BSD), Interoperable Location Service Daemon (ILSD), and Location Service
Daemon (LSD) might be called upon, and Comm Servers (CS) might be used. If Comm Servers are used, the LSD must also be used. The
communication services are supported by the URL directories and the configuration database.
The Common Object Services include Transaction Services (which are supported by TMF), Naming Services, and Event Services. The Naming
Service and Interface Repository maintain databases to support their services.
The Interface Repository also acts as a service, though it is not one of the OMG-defined Common Object Services.
Servers have a Portable Object Adapter (POA) manager and may have one or more POAs. POAs contain policies governing the Servant Class shown
in the figure. (POA policies are a complex subject. For more information see a standard CORBA reference. The NonStop CORBA-specific POA
stateful and stateless policies are described in Writing Scalable Applications.)
Figure A.2. Expanded View of NonStop CORBA Architecture