INTERNATIONAL  TELECOMMUNICATION  UNION

		     ITU-T RECOMMENDATION SUMMARY


Rec. No. : I.255.4

Title : Priority service

Study Group : I - Services

Version : New

Date of adoption : 1990

Notes :	


The Priority service provides for preferential treatment in the 
network to calls originating from and/or addressed to certain numbers 
in the order of path selection.

This service provides preferential treatment in the network for calls:

	-   originating from subscribers' lines. This is designated as 
	    A-priority; and/or

	-   addressed to certain emergency numbers. This is designated 
	    as B-priority and concerns the order of path selection in 
	    the ISDN.

For A-priority, subscribers' lines are classified into two A-priority 
categories which are:

	-   subscribers with first order priority (I) for all calls;

	-   subscribers with first order priority (II) on a per call 
	    basis.

Only one B-priority category is envisaged.



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