INTERNATIONAL  TELECOMMUNICATION  UNION

		     ITU-T RECOMMENDATION SUMMARY


Rec. No. : X.650

Title :	Open systems interconnection (OSI) - reference model for naming 
	and addressing

Study Group : VII - Data Communications Networks

Version : New

Date of adoption : 1992

Notes :	


Recommendation X.650 extends the basic architectural concepts of 
identifiers described in Recommendation X.200.

Recommendation X.650 states the architectural principles which are 
followed in the production ot any Recommendation which involves the 
identification (naming) and location (addressing) of objects for the 
purpose of interconnection within the Open System Interconnection 
Environment (OSIE). It has sufficient flexibility to accommodate 
advances in technology and expansion in user demands. This flexibility 
is also intended to allow the phased transition from existing 
implementations to  OSI Recommendations.

Recommendation X.650 is expected to be subject to future expansion, in 
particular with regard to Multi-Peer Data Transmission (MPDT).

The architectural principles stated within Recommendation X.650 will 
ensure that any CCITT Recommendation that involves the identification 
and location of objects within the OSIE for the purpose of 
interconnection will:

	a) avoid any restrictions on:

	1) the functionality that may be made available through 
	   current of future Recommendations,

	2) the functionality of any real open system,

	3) the internal design of any real open system;

	b) preserve the principle of layer independence in the OSIE, 
	   i.e. the internal functioning of one layer is not 
	   constrained by any other layer;

	c) preserve the principle of implementation independence in 
	   the OSIE, as expressed in Recommendation X.200. That is, 
	   no real open system (or administrator thereof) is required 
	   to know anything about the implementation design of any 
	   other real open system (or administration thereof), nor 
	   does any real open system impose such knowledge as a 
	   condition for communication using OSI Recommendations;

	d) allow economical support for interconnection within the 
	   OSIE.



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