New York
University
Computer
Science Department
Courant
Institute of Mathematical Sciences
Object
Request Brokers (ORB) Interoperability
Course Title: Application Servers Course
Number: g22.3033-011
Instructor: Jean-Claude Franchitti Session: 4
Because CORBA is
implementation free, a common network protocol is required so different
implementations are able to interact. The GIOP (General Inter-ORB Protocol) is
specified as the common interface, including message type and format, that is
required for general interoperability.
A semantic layer, the IIOP
(Internet Inter-Orb Protocol) is specified to map the GIOP into TCP/IP. This
combination of GIOP and IIOP is necessary for out-of-the-box interoperability
support. All ORB vendors supporting this protocol should interoperate.
However, a single protocol
is not correct for all uses or purposes, so it is possible for the GIOP to be
mapped into different protocols (such as IPX or SNA).
A single set of interfaces
may not be correct for all purposes. In this case, ESIOP (Environment Specific
Inter-ORB Protocols) are of interest. The first ESIOP specified is one based on
DCE. The DCE-CIOP (DCE Common Inter-ORB Protocol) acts as the glue between the
ESIOP and TCP for those specific environments where the DCE protocol is useful.