Section: 4.3.2.6 Abnormal cases
Content: (a) RR connection failure: Upon detection of a RR connection failure before the AUTHENTICATION RESPONSE message is received, the network shall release all MM connections (if any) and abort any ongoing MM specific procedure. (b) Expiry of timer T3260: The authentication procedure is supervised on the network side by the timer T3260. At expiry of this timer the network may release the RR connection. In this case the network shall abort the authentication procedure and any ongoing MM specific procedure, release all MM connections if any, and initiate the RR connection release procedure described in subclause 3.5 of 3GPP TS 44.018[ None ]  [84] (A/Gb mode only), 3GPP TS 25.331[ None ]  [23c] (UTRAN Iu mode only), or in 3GPP TS 44.118[ None ]  [111] (GERAN Iu mode only). (c) Authentication failure (reject cause "MAC failure" or "GSM authentication unacceptable"): The MS shall send an AUTHENTICATION FAILURE message, with reject cause "MAC failure" or "GSM authentication unacceptable" according to subclause 4.3.2.5.1, to the network and start timer T3214. Furthermore, the MS shall stop any of the retransmission timers that are running (e.g. T3210, T3220 or T3230). Upon the first receipt of an AUTHENTICATION FAILURE message from the MS with reject cause "MAC failure" or "GSM authentication unacceptable", the network may initiate the identification procedure described in subclause 4.3.3. This is to allow the network to obtain the IMSI from the MS. The network may then check that the TMSI originally used in the authentication challenge corresponded to the correct IMSI. Upon receipt of the IDENTITY REQUEST message from the network, the MS shall send the IDENTITY RESPONSE message. NOTE: Upon receipt of an AUTHENTICATION FAILURE message from the MS with reject cause "MAC failure" or "GSM authentication unacceptable", the network may also terminate the authentication procedure (see subclause 4.3.2.5). If the TMSI/IMSI mapping in the network was incorrect, the network should respond by sending a new AUTHENTICATION REQUEST message to the MS. Upon receiving the new AUTHENTICATION REQUEST message from the network, the MS shall stop the timer T3214, if running, and then process the challenge information as normal. If theTMSI/IMSI mapping in the network was correct, the network should terminate the authentication procedure by sending an AUTHENTICATION REJECT message. If the network is validated successfully (an AUTHENTICATION REQUEST message that contains a valid SQN and MAC is received), the MS shall send the AUTHENTICATION RESPONSE message to the network and shall start any retransmission timers (e.g. T3210, T3220 or T3230), if they were running and stopped when the MS received the first failed AUTHENTICATION REQUEST message. If the MS receives the second AUTHENTICATION REQUEST message while T3214 is running, and the MAC value cannot be resolved or the message contains a GSM authentication challenge, the MS shall follow the procedure specified in this subclause (c), starting again from the beginning. If the SQN is invalid, the MS shall proceed as specified in (d). It can be assumed that the source of the authentication challenge is not genuine (authentication not accepted by the MS) if any of the following occur: - the timer T3214 expires; - the MS detects any combination of the authentication failures: "MAC failure", "invalid SQN", and "GSM authentication unacceptable", during three consecutive authentication challenges. The authentication challenges shall be considered as consecutive only, if the authentication challenges causing the second and third authentication failure are received by the MS, while the timer T3214 or T3216 started after the previous authentication failure is running. The MS shall stop timer T3214, if the timer is running and the MS detects an RR connection failure or the network releases the RR connection. When it has been deemed by the MS that the source of the authentication challenge is not genuine (i.e. authentication not accepted by the MS), the MS shall behave as described in subclause 4.3.2.6.1. Figure 4.2/3GPP TS 24.008[ Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 ] : Authentication Failure Procedure (reject cause "MAC failure" or "GSM authentication unacceptable") (d) Authentication failure (reject cause "synch failure"): The MS shall send an AUTHENTICATION FAILURE message, with reject cause "synch failure", to the network and start the timer T3216. Furthermore, the MS shall stop any of the retransmission timers that are running (e.g. T3210, T3220 or T3230). Upon the first receipt of an AUTHENTICATION FAILURE message from the MS with the reject cause "synch failure", the network shall use the returned AUTS parameter from the authentication failure parameter IE in the AUTHENTICATION FAILURE message, to re-synchronise. The re-synchronisation procedure requires the VLR/MSC to delete all unused authentication vectors for that IMSI and obtain new vectors from the HLR. When re-synchronisation is complete, the network shall initiate the authentication procedure. Upon receipt of the AUTHENTICATION REQUEST message, the MS shall stop the timer T3216, if running. NOTE: Upon receipt of two consecutive AUTHENTICATION FAILURE messages from the MS with reject cause "synch failure", the network may terminate the authentication procedure by sending an AUTHENTICATION REJECT message. If the network is validated successfully (a new AUTHENTICATION REQUEST message is received which contains a valid SQN and MAC) while T3216 is running, the MS shall send the AUTHENTICATION RESPONSE message to the network and shall start any retransmission timers (e.g. T3210, T3220 or T3230), if they were running and stopped when the MS received the first failed AUTHENTICATION REQUEST message. If the MS receives the second AUTHENTICATION REQUEST message while T3216 is running, and the MAC value cannot be resolved or the message contains a GSM authentication challenge, the MS shall proceed as specified in (c); if the SQN is invalid, the MS shall follow the procedure specified in this subclause (d), starting again fom the beginning. The MS shall deem that the network has failed the authentication check and behave as described in subclause 4.3.2.6.1, if any of the following occurs: - the timer T3216 expires; - the MS detects any combination of the authentication failures: "MAC failure", "invalid SQN", and "GSM authentication unacceptable", during three consecutive authentication challenges. The authentication challenges shall be considered as consecutive only, if the authentication challenges causing the second and third authentication failure are received by the MS, while the timer T3214 or T3216 started after the previous authentication failure is running. The MS shall stop timer T3216, if the timer is running and the MS detects an RR connection failure or the network releases the RR connection. When it has been deemed by the MS that the source of the authentication challenge is not genuine (i.e. authentication not accepted by the MS), the MS shall behave as described in subclause 4.3.2.6.1. Figure 4.2a/3GPP TS 24.008[ Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 ] : Authentication Failure Procedure (reject cause "Synch failure") Upon receipt of an AUTHENTICATION REJECT message, the mobile station shall perform the actions as specified in subclause 4.3.2.5. If an MS has an MM connection for an emergency call established or is establishing an MM connection for an emergency call when timer T3214 or T3216 expires, the MS shall not deem that the network has failed the authentication check and not behave as described in subclause 4.3.2.6.1.