Question: What happens when a Mobile Station (MS) or Gateway GPRS Support Node (GGSN) attempts to create or modify a Traffic Flow Template (TFT) without including at least one valid packet filter?
Option 1: The TFT creation/modification procedure succeeds, but with a warning message sent to the MS or GGSN.
Option 2: The existing TFT is automatically deleted to accommodate the new change.
Option 3: The procedure used for the creation or modification of the TFT fails, and an error code is returned to the MS or GGSN respectively.
Option 4: The MS or GGSN defaults to a predefined packet filter to complete the TFT creation/modification.
Explanation: This is because, according to the rules for operations on TFTs, if no valid packet filter is included in the newly created or modified TFT, the procedure will fail as a safeguard to ensure proper filtering and network management. This highlights the importance of packet filters in managing and securing data traffic within GPRS networks.