Section: 4.3.2.3 Authentication processing in the network
Content: Upon receipt of the AUTHENTICATION RESPONSE message, the network stops the timer T3260 and checks the validity of the response (see 3GPP TS 43.020[ Security related network functions ]  [13] in case of a GSM authentication challenge respective 3GPP TS 33.102[ 3G security; Security architecture ]  [5a] in case of an UMTS authentication challenge). Upon receipt of the AUTHENTICATION FAILURE message, the network stops the timer T3260. In Synch failure case, the core network may renegotiate with the HLR/AuC and provide the MS with new authentication parameters.