Background

Open Systems Interconnection (OSI) is an internationally standardized architecture that permits communications between different types of computer systems. The elements of OSI are defined in more than 100 standards, standardized profiles and technical reports developed by the International Organization for Standardization (ISO ), the International Electrotechnical Commission (IEC ) and the International Telecommunication Union (ITU ).

Fundamental to the successful operation of OSI is the ability to identify and locate people, applications, systems, networks, and data structures.

Names and addresses used to establish communications must be completely unambiguous if confusion and chaos are to be avoided. An unambiguous name is one that identifies one and only one object within the entire open systems environment. To ensure this unambiguity the names and addresses need to be registered.

Registration Authorities
ISO and IEC have established an international structure of registration authorities to ensure the assignment of names and addresses that will be unique regardless of where in the world they are used.

The Standards Council of Canada , Canada's ISO member body, has appointed the Government Telecommunications and Informatics Services (GTIS) branch of Public Works and Government Services Canada (PWGSC) as the Canadian OSI Registration Authority (COSIRA).

GTIS has also been appointed the Government of Canada OSI Registration Authority (GORA).

The COSIRA mandate is to establish and maintain an OSI registry of organizations and identities officially registered in Canada. Specifically it:

1. accepts and processes new applications for registration in the OSI registry at the national level;
2. ensures that all names are unique at the national level; and
3. maintains and publishes the OSI registry at the national level.

The GORA mandate is to perform the same function for Government of Canada organizations such as departments and agencies.

Naming and Addressing

The definition of terms such as "Name" and "Address" for OSI information objects is given in the international standard ISO 7498-3: Information technology -- Open Systems Interconnection -- Basic Reference Model - Part 3: Naming and addressing. A name is a "linguistic construct", expressed in some language, used to identify an object.

The standards define four name spaces for registering different types of OSI information objects:

1. organization Identifiers for use in the Data Country Code (DCC) scheme of network layer service access point (NSAP) addressing;
2. object identifiers (OID) used to uniquely identify objects such as data formats used in communications protocols and application programs;
3. "Relative Distinguished Names" (RDNs) and "Distinguished Names" (DNs) used in the assignment of X.500 directory names; and
4. "Administrative Management Domain (ADMD)" and "Private Management Domain (PRMD)" names used in X.400 messaging services.

Each of the name spaces forms a hierarchical structure that is modelled as an inverted tree. ISO, IEC* and ITU are responsible for defining the trees and registering information objects. They have delegated responsibility for establishing and administering registered names below the national level to their national bodies, such as the Standards Council. The Standards Council, in turn, has delegated functional responsibility for registration to GTIS.

Obtaining the standards
The best source for more information on OSI is the OSI documents themselves.

ISO and IEC standards may be obtained through IHS Canada .

Many of ISO and IEC's OSI standards have been adopted as Canadian standards by CSA International . To order copies of the Canadian editions, please contact CSA.

*International Electrotechnical Commission.