Question: How does the Packet Data Network Gateway (P-GW) handle downlink Non-IP data in an SGi Point-to-Point (PtP) tunneling mechanism?
Option 1: The P-GW sends the data directly to the User Equipment (UE) over the GTP-U tunnel.
Option 2: The P-GW forwards the received data from the Application Server (AS) to the Serving Gateway (S-GW) on a different SGi PtP tunnel.
Option 3: The P-GW establishes a new SGi PtP tunnel for each downlink Non-IP data packet.
Option 4: The AS sends the data to the P-GW over the established SGi PtP tunnel, and then the P-GW sends it to the S-GW on the GTP-U tunnel identified by the associated SGi PtP tunnel.
Explanation: In an SGi PtP tunneling mechanism, when downlink Non-IP data is received from the Application Server (AS), the AS locates the correct SGi PtP tunnel for the User Equipment (UE) and sends the data to the Packet Data Network Gateway (P-GW) over that tunnel. The P-GW then forwards this data to the Serving Gateway (S-GW) on the GTP-U tunnel associated with the SGi PtP tunnel, which ultimately delivers it to the UE.