GIOP
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In distributed computing, GIOP (General Inter-ORB Protocol) is the abstract protocol by which Object request brokers (ORBs) communicate. Standards associated with the protocol are maintained by the Object Management Group (OMG).
IIOP (Internet Inter-Orb Protocol) is the implementation of GIOP for TCP/IP.
The Object Management Group defines four parts of GIOP:
- the Common Data Representation (CDR) - transfer syntax mapping OMG IDL data types into a low-level representation for “on-the-wire” transfer between ORBs and Inter-ORB bridges.
- Interoperable Object Reference (IOR) - define the format of a reference to a remote object. An IOR contains:
- Version Number of the server protocol
- Server address
- A byte sequence identifying the remote object
- message formats - messages are exchanged between agents to facilitate object requests, locate object implementations, and manage communication channels. Messages are:
- Request
- Reply
- CancelRequest
- LocateRequest
- LocateReply
- CloseConnection
- MessageError
- Fragment
- message-transport assumptions
- connection orientated
- reliable
- can be viewed as a byte stream
- provides some reasonable notification of disorderly connection loss
- model for initiating connections can be mapped onto the general connection model of TCP/IP.