Question: What is the primary function of the PDN GW in the Evolved Packet Core (EPC) architecture?
Option 1: To provide mobility management for User Equipment (UEs)
Option 2: To act as a gateway between the E-UTRAN and the external packet data network
Option 3: To terminate the SGi interface towards the PDN and perform functions such as per-user based packet filtering, lawful interception, and UE IP address allocation
Option 4: To manage the radio resources of the E-UTRAN
Explanation: The PDN GW is a critical component in the EPC architecture that terminates the SGi interface towards the PDN. Its primary function is to perform various tasks such as per-user based packet filtering, lawful interception, UE IP address allocation, and more. This ensures secure and efficient data transfer between the UE and the external packet data network.