Question: In IPv6 Prefix Delegation for a PDU Session, if the UP function determines the IPv6 prefix length, how should the CP function set the IPv6 Prefix Delegation Bits or IPv6 Prefix Length fields in the UE IP Address IE?
Option 1: Set to "0"
Option 2: Set according to the default /64 prefix length
Option 3: Set to the maximum possible value for delegation
Option 4: Not set, as it's determined by the UP function
Explanation: According to the specification, when the IPv6 prefix length is determined by the UP function (instead of the CP function), the CP function should indicate this by setting the IPv6 Prefix Delegation Bits or IPv6 Prefix Length fields to "0", allowing the UP function to decide on the prefix length. This ensures flexibility in managing IPv6 address space for PDU Sessions, especially in scenarios where additional prefixes beyond the default might be needed.