Question: What is a key capability that the system must support when two different network domains (PLMNs) are interconnected for 2G and 3G CS services using IP transport technology?
Option 1: Automatic handover of sessions from one domain to another without user intervention.
Option 2: Support for only a single, standardized IP addressing scheme across both domains.
Option 3: Encryption of all signaling and traffic exclusively with a predefined protocol.
Option 4: Control of session resources to accommodate different IP addressing schemes in each domain.
Explanation: This is correct because when interconnecting two different network domains (PLMNs) for CS services, the system must manage and control session resources effectively. This includes handling potential discrepancies such as different IP addressing schemes in each domain, ensuring seamless service delivery across the interconnected networks.