Question: In an EPS (Evolved Packet System) with a mix of IPv4 and IPv6 eNodeBs and/or backhauls, how does the MBMS Gateway (MBMS GW) handle IP Multicast address distribution for E-UTRAN access if it supports both IPv4 and IPv6?
Option 1: The MBMS GW chooses only one IP Multicast address, which is always in IPv6 format for compatibility.
Option 2: The MBMS GW selects an IP Multicast address exclusively for IPv4 to ensure backward compatibility.
Option 3: The MBMS GW can choose both an IPv4 and an IPv6 IP Multicast address for distribution, depending on the deployment.
Option 4: The decision is left entirely to the downstream MMEs (Mobility Management Entities) without input from the MBMS GW.
Explanation: This option correctly reflects the capability of the MBMS GW in deployments with mixed IPv4 and IPv6 environments for E-UTRAN access. By choosing both an IPv4 and an IPv6 IP Multicast address, the MBMS GW ensures compatibility across different network configurations, facilitating efficient multimedia broadcast/multicast service (MBMS) delivery. This approach aligns with the need for flexibility in heterogeneous network deployments, ensuring that MBMS services can be effectively distributed regardless of the IP version used by eNodeBs and/or backhauls.