Question: What action does the PCEF take when it receives a downlink packet that doesn't match any of the service data flow templates in the active PCC rules for a UE's PDP address?
Option 1: The PCEF tunnels the packet to the SGSN via a default PDP context.
Option 2: The PCEF silently discards the packet.
Option 3: The PCEF sends a request to the PCRF for new PCC rules.
Option 4: The PCEF buffers the packet awaiting further instructions.
Explanation: If the PCEF finds no matching service data flow template in the active PCC rules for a UE's PDP address, it silently discards the packet. This ensures packets without a defined route aren't misrouted or cause unnecessary network load, highlighting precise packet handling importance in telecom networks.