Section: 5.4.4.2.2 Clearing when the network indicates that "CCBS activation is possible"
Content: When Activation of CCBS is possible, the call control entity of the network may initiate clearing by sending a DISCONNECT message containing the Allowed Actions IE with an indication that "Activation of CCBS is possible" and starting T338. Optionally, progress indicator #8 "in-band information or appropriate pattern now available" may also be contained in the DISCONNECT message (in which case, T338 shall not be greater than T306). 5.4.4.2.2.1 Receipt of a DISCONNECT Relative to the current state the following procedures apply: - The call control entity of the MS in the "null" state, the "disconnect indication" state and the "release request" state, shall, upon receipt of a DISCONNECT message react as described in clause 8. - The call control entity of the MS in the "disconnect request" state, shall, upon receipt of a DISCONNECT message: - stop all running call control timers; - send a RELEASE message; - start timer T308; and - enter the "release request" state. - The call control entity of the MS in any other states, shall, upon receipt of a DISCONNECT message with an Allowed Actions IE indicating "Activation of CCBS is possible" pass the "Activation of CCBS is possible" indication to the upper layer, enter the "disconnect indication" state, stop all running call control timers and await a response from the upper layers. If the DISCONNECT message contained the progress indicator #8 "in-band information or appropriate pattern now available" and an appropriate speech traffic channel is connected, then the MS shall attach the user connection for speech if it is not yet attached. If the DISCONNECT message did not contain the progress indicator #8 "in-band information or appropriate pattern now available" any connected speech traffic channel shall be disconnected. Response from the upper layers: i) If the upper layers request the clearing of the call, the call control entity of the MS shall: - stop all running call control timers; - send a RELEASE message; - start timer T308; and - enter the "release request" state. ii) If the upper layers request that the "CCBS activation is to be attempted" then the MS shall - send a RELEASE message containing a Facility IE including an - Invoke=CCBSRequest to the network; - stop all running call control timers; - start timer T308; and - enter the "release request" state. If an appropriate speech traffic channel is connected, transmission of this RELEASE message shall not cause it to be disconnected. 5.4.4.2.2.2 Expiry of timer T338 The call control entity of the network, having entered the "disconnect indication" state after sending a DISCONNECT message with an Allowed Actions IE indicating "Activation of CCBS is possible" shall, upon expiry of timer T338, continue clearing by sending a RELEASE message with the cause number originally contained in the DISCONNECT message; starting timer T308; and entering the "release request" state.