INTERNATIONAL TELECOMMUNICATION UNION ITU-T RECOMMENDATION SUMMARY Rec. No. : Q.733.1 Title : Stage 3 Description for call completion supplementary services using signalling system No. 7 Study Group : XI - Switching and Signalling Version : New Date of adoption : 1992 Notes : CALL WAITING (CW) The CW supplementary service permits a subscriber to be notified of an incoming call (as per basic call procedures) with an indication that no interface information channel is available. The user then has the choice of accepting, rejecting or ignoring the waiting call (as per basic call procedures). To order the complete text of this Recommendation, please use the Order Form for ITU-T Recommendations. An electronic version of this form is available on ITUDOC (Winword 2.0: UPI=ITU-5265; ASCII: UPI=ITU-2488).