Question: Upon receiving an SGsAP-ALERT-REJECT message, what action does the Visitor Location Register (VLR) take regarding the timer Ts7 and the state of the SGs association?
Option 1: The VLR resets timer Ts7 and moves the SGs association state to SGs-ACTIVE.
Option 2: The VLR stops timer Ts7 and moves the state of the SGs association to SGs-NULL, marking it with the SGs cause information element.
Option 3: The VLR starts a new timer (Ts8) and maintains the current SGs association state.
Option 4: The VLR ignores the message and continues with the existing configuration.
Explanation: When an SGsAP-ALERT-REJECT message is received, indicating a failure in the alert process, the VLR must cease the ongoing attempt (stop timer Ts7) and revert the association state to its null or inactive state (SGs-NULL), while also updating this state with the reason for the rejection (SGs cause information element). This ensures the system accurately reflects the current status and the reason for the alert failure, facilitating potential retries or alternative actions.