| Previous | Table of Contents | Next |
Domains allow partitioning of systems into collections of components which have some characteristic in common. In this architecture
a domain is a scope in which a collection of objects, said to be members of the domain, is associated with some common characteristic;
any object for which the association does not exist, or is undefined, is not a member of the domain. A domain can be modeled
as an object and may be itself a member of other domains.
It is the scopes themselves and the object associations or bindings defined within them which characterize a domain. This
information is disjoint between domains. However, an object may be a member of several domains, of similar kinds as well as
of different kinds, and so the sets of members of domains may overlap.
The concept of a domain boundary is defined as the limit of the scope in which a particular characteristic is valid or meaningful.
When a characteristic in one domain is translated to an equivalent in another domain, it is convenient to consider it as traversing
the boundary between the two domains.
Domains are generally either administrative or technological in nature. Examples of domains related to ORB interoperability
issues are:
• Referencing domain – the scope of an object reference
• Representation domain – the scope of a message transfer syntax and protocol
• Network addressing domain – the scope of a network address
• Network connectivity domain – the potential scope of a network message
• Security domain – the extent of a particular security policy
• Type domain – the scope of a particular type identifier
• Transaction domain – the scope of a given transaction service
Domains can be related in two ways: containment, where a domain is contained within another domain, and federation, where
two domains are joined in a manner agreed to and set up by their administrators.