Question: What action does a receiving node take when it receives a message with a Procedure Code IE marked as 'Ignore IE and Notify Sender' that it cannot comprehend?
Option 1: The receiving node rejects the procedure using the Error Indication procedure without notifying the sender.
Option 2: The receiving node ignores the procedure but does not initiate any further action.
Option 3: The receiving node comprehensively logs the error for later analysis but takes no immediate procedural action.
Option 4: The receiving node ignores the procedure and initiates the Error Indication procedure to notify the sender.
Explanation: When a receiving node cannot comprehend a Procedure Code IE marked as 'Ignore IE and Notify Sender', it ignores the procedure but also notifies the sender of the issue by initiating the Error Indication procedure.