Question: In an MBMS (Multimedia Broadcast/Multicast Service) download session, how is the IP source address defined in the SDP (Session Description Protocol) description for both IPv4 and IPv6 sources?
Option 1: Using multiple source-filter attributes with exclusive-mode for each source address.
Option 2: With a single source-filter attribute ("a=source-filter:") in inclusive-mode, specifying exactly one source address in the <src-list>, located in the session part of the SDP description.
Option 3: By listing all possible IP addresses in the <dest-address> subfield without using the source-filter attribute.
Option 4: Through a separate source-filter attribute for each media type in the SDP description.
Explanation: The correct approach for defining the IP source address in an MBMS download session's SDP description is to use a single source-filter attribute ("a=source-filter:") in inclusive-mode. This attribute should specify exactly one source address in the <src-list> and be located in the session part of the SDP description, not per media. This ensures consistency and clarity for both IPv4 and IPv6 sources, aligning with the principles outlined for MBMS download sessions.