Question: What is the primary purpose of setting up CC links as CUG (Closed User Group) calls for Handover Interface in Lawful Interception (LI), and how do the specified CUG parameter settings achieve this?
Option 1: To restrict access to the Law Enforcement Agency (LEA), achieved by disallowing incoming and outgoing accesses, while permitting internal calls within the CUG but barring outgoing calls to external numbers.
Option 2: To enhance call quality for LEA communications, achieved by allowing both incoming and outgoing accesses, enabling internal calls, and permitting outgoing calls to external numbers.
Option 3: To simplify billing for LI operations, achieved by allowing incoming access, disallowing outgoing access, and restricting all calls within the CUG.
Option 4: To increase security for non-LEA entities, achieved by disallowing incoming accesses, allowing outgoing accesses, and enabling internal and external calls.
Explanation: Setting up CC links as CUG calls primarily aims to prevent unauthorized connections to the LEA, enhancing security. The specified settings achieve this by preventing external initiations, restricting unintended external calls, allowing intended internal communications, and securing the LEA's communication boundary from accidental outreach.