Question: What is the mandatory mode of operation for IPsec implementation in a 5G system?
Option 1: Tunnel mode
Option 2: Transport mode
Option 3: Both tunnel and transport modes are optional
Option 4: Neither tunnel nor transport mode is specified
Explanation: According to the security architecture and procedures for 5G systems, IPsec implementation must support tunnel mode mandatorily, while transport mode is optional. This ensures secure communication between network entities in a 5G system.