Question: What determines which GTP-U tunnel a particular T-PDU belongs to when multiplexed between two Tunnel Endpoints?
Option 1: Source IP Address of the GGSN
Option 2: Destination Port Number in the UDP Header
Option 3: Tunnel Endpoint ID (TEID) in the GTP Header
Option 4: Type of PDP Context Assigned
Explanation: In GTP-U, the Tunnel Endpoint ID (TEID) within the GTP header identifies and differentiates between multiple tunnels established between a pair of GTP-U Tunnel Endpoints, ensuring proper routing of encapsulated T-PDUs and signaling messages.