CORBA 2.6.1 Programmer's Guide for C++

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