INTERNATIONAL  TELECOMMUNICATION  UNION

		     ITU-T RECOMMENDATION SUMMARY


Rec. No. : E.164

Title :	Numbering  plan  for  the  ISDN  era

Study Group : II - Network Operation

Version : Revised

Date of adoption : 1991

Notes :	Identical with I.331


The rapid advances in telecommunications technology coupled with 
increased diversification of customer demands served by a number of 
different types of dedicated public switched networks (telephone, 
telex, data, etc.) have created a need to provide a uniform customer 
access and network structure. Such a structure is called the 
integrated services digital network (ISDN). Implementation of ISDNs 
has begun in a number of countries and eventually these will carry the 
full range of existing and new services.

To provide a broad base for the growth of ISDN arrangements, numbering 
has been kept compatible with that originally established for the 
international telephone service. As recounted in Recommendation E.164, 
numbering for the international telephone service is a subset of the 
numbering plan for the ISDN era. The timetable for implementation of 
new provisions introduced primarily to support the ISDN era is 
described in Recommendation E.165.



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