Section: 5.2.2.3.3 Call failure procedures
Content: In case of abnormal behaviour the following call failure procedures apply: i. If the network does not receive any response to the SETUP message prior to the expiration of timer T303, then the network shall: initiate clearing procedures towards the calling user with cause #18 "no user responding"; and initiate clearing procedures towards the called mobile station in accordance with subclause 5.4.4 using cause #102 "recovery on timer expiry". ii. If the network has received a CALL CONFIRMED message, but does not receive an ALERTING, CONNECT or DISCONNECT message prior to the expiration of timer T310, then the network shall: - initiate clearing procedures towards the calling user with cause #18 "no user responding"; and - initiate clearing procedures towards the called MS in accordance with subclause 5.4.4 using cause #102 "recovery on timer expiry". iii. If the network has received an ALERTING message, but does not receive a CONNECT or DISCONNECT message prior to the expiry of timer T301 (or a corresponding internal alerting supervision timing function), then the network shall: initiate clearing procedures towards the calling user with cause #19 "user alerting, no answer"; and initiate clearing procedures towards the called mobile station in accordance with subclause 5.4.4, using cause #102 "recovery on timer expiry" or using cause #31 "normal, unspecified". NOTE: The choice between cause #31 and cause #102 may have consequences on indications generated by the mobile station, see 3GPP TS 22.001[ Principles of circuit telecommunication services supported by a Public Land Mobile Network (PLMN) ]  [8a].