An Interoperable Object Reference (IOR) is a CORBA

Çorba

Chorba , ciorbă , shurpa , shorpo , or sorpa is one of various kinds of soup or stew found in national cuisines across Middle East...

 or RMI-IIOP

RMI-IIOP

RMI-IIOP denotes the Java Remote Method Invocation interface over the Internet Inter-Orb Protocol , which delivers Common Object Request Broker Architecture distributed computing capabilities to the Java 2 platform...

 reference

Reference (computer science)

In computer science, a reference is a value that enables a program to indirectly access a particular data item, such as a variable or a record, in the computer's memory or in some other storage device. The reference is said to refer to the data item, and accessing those data is called...

 that uniquely identified an object

Object (computer science)

In computer science, an object is any entity that can be manipulated by the commands of a programming language, such as a value, variable, function, or data structure...

 on a remote CORBA server.

IORs can be transmitted in binary over TCP/IP via the General Inter-ORB Protocol (the encoding may be big-endian or little-endian

Endianness

In computing, the term endian or endianness refers to the ordering of individually addressable sub-components within the representation of a larger data item as stored in external memory . Each sub-component in the representation has a unique degree of significance, like the place value of digits...

), or serialized into a string of hexadecimal digits (prefixed by the string IOR:) to facilitate transport by non-CORBA mechanisms such as HTTP, FTP

File Transfer Protocol

File Transfer Protocol is a standard network protocol used to transfer files from one host to another host over a TCP-based network, such as the Internet. FTP is built on a client-server architecture and utilizes separate control and data connections between the client and server...

, and e-mail

E-mail

Electronic mail, commonly known as email or e-mail, is a method of exchanging digital messages from an author to one or more recipients. Modern email operates across the Internet or other computer networks. Some early email systems required that the author and the recipient both be online at the...

.

The internal structure of an IOR may contain multiple components. Each component is identified by its integer code and has its own binary format. The codes are assigned by the Object Management Group

Object Management Group

Object Management Group is a consortium, originally aimed at setting standards for distributed object-oriented systems, and is now focused on modeling and model-based standards.- Overview :...

. The typical IOR normally contains the IP address of the remote host, the number of the remote port on that the CORBA server is listening, a string defining the class of the remote object on which the methods will be invoked, and the object key that is used by the server ORB to identify the object.

It is possible to register special objects (IOR interceptors) that can add the needed specific components to the IOR being created by the particular ORB

Object request broker

In distributed computing, an object request broker is a piece of middleware software that allows programmers to make program calls from one computer to another via a network...

.