Question: Which protocol(s) are mandated for the CSC-7 reference point to handle subscription/notification related signalling between group management servers in the same security domain?
Option 1: SIP-2 and SIP-3
Option 2: HTTP-1, HTTP-2, and HTTP-3
Option 3: Both SIP (SIP-2, SIP-3) for subscription/notification and HTTP (HTTP-1, HTTP-2, HTTP-3) for non-subscription/notification
Option 4: Only SIP-3 when served by the same SIP core
Explanation: According to specifications, subscription/notification related signalling requires using SIP-2 and SIP-3. Both are designated for this type of signalling, making Option 1 correct.