INTERNATIONAL  TELECOMMUNICATION  UNION

		     ITU-T RECOMMENDATION SUMMARY


Rec. No. : Q.83.2

Title :	Stage 2 description for call completion supplementary services

Study Group : XI - Switching and Signalling

Version : Revised

Date of adoption : 1992

Notes :	


			     CALL HOLD

Recommendation Q.83.2 defines the stage 2 of the Call Hold (CH) 
supplementary service. Stage 2 identifies the functional capabilities 
and the information flows needed to support the service as described 
in stage 1. The stage 2 description also identifies user operations 
not directly associated with a call (see Recommendation I.130).

Recommendation Q.83.2 is specified according to the methodology 
specified in Recommendation Q.65.

In addition, Recommendation Q.83.2 does not specify the requirements 
where the service is provided to the user via a private ISDN. 
Recommendation Q.83.2 does not specify the requirements for the 
allocation of defined functional entities within a private ISDN, it 
does however define which functional entities may be allocated to a 
private ISDN.

Recommendation Q.83.2 does not specify the additional requirements 
where the service is provided to the user via a telecommunications 
network that is not an ISDN.

The Call Hold service allows a user to interrupt communications on an 
existing call/connection and then subsequently, if desired, 
re-establish communications. A B-channel may or may not be reserved 
after the communication is interrupted to allow the origination or 
possible termination of other calls. Reservation must be provided by 
the service provider as a user option. The Call Hold service includes 
the retrieve operation which re-establishes communication on a 
B-channel between the served user and the held party.

This supplementary service is not applicable to non-voice services.

Recommendation Q.83.2 is applicable to the stage 3 Recommendations 
for the integrated services digital network.



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