Method and apparatus for adding notifications related with user equipment multicast group and leave

A method comprising:

• causing a user plane function to report when a protocol data unit session has been added to or removed from a downlink replication tree associated with an internet protocol multicast flow;
• receiving, from the user plane function, a message indicating that a protocol data unit session has been added to or removed from the downlink replication tree associated with the internet protocol multicast flow, said message comprising at least an internet protocol address associated with a multicast destination of said internet protocol multicast flow;
• and
• forwarding the indication that a protocol data unit session has been added to or removed from the downlink replication tree associated with the internet protocol multicast flow to entities that have requested to be notified in an instance in which a protocol data unit session has been added to or removed from the downlink replication tree associated with the internet protocol multicast flow.

An apparatus comprising at least one processor and at least one memory including computer program code for one or more programs, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:

• receive, from a session controller, a request for reporting when protocol data unit sessions are added to or removed from a downlink replication tree associated with an internet protocol multicast flow;
• determine whether a protocol data unit session has been added to or removed from the downlink replication tree associated with the internet protocol multicast flow;
• and
• in response to said determining, transmit a message to a session management function indicate that said protocol data unit session has been added to or removed from said downlink replication tree,
• wherein said message comprises an internet protocol address associated with a multicast destination of said internet protocol multicast flow.

An apparatus comprising at least one processor and at least one memory including computer program code for one or more programs, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:

• cause a user plane function to report when a protocol data unit session has been added to or removed from a downlink replication tree associated with an internet protocol multicast flow;
• receive, from the user plane function, a message indicating that a protocol data unit session has been added to or removed from the downlink replication tree associated with the internet protocol multicast flow, said message comprising at least an internet protocol address associated with a multicast destination of said internet protocol multicast flow;
• and
• forward the indication that a protocol data unit session has been added to or removed from the downlink replication tree associated with the internet protocol multicast flow to entities that have been requested to be notified in an instance in which a protocol data unit session has been added to or removed from the downlink replication tree associated with the internet protocol multicast flow.

A computer program product comprising at least one non-transitory computer-readable storage medium having computer-executable program code instructions stored therein, the computer-executable program code instructions comprising program code instructions configured, upon execution, to:

• receive, from a session controller, a request for reporting when protocol data unit sessions are added to or removed from a downlink replication tree associated with an internet protocol multicast flow;
• determine whether a protocol data unit session has been added to or removed from the downlink replication tree associated with the internet protocol multicast flow;
• and
• in response to said determining, transmit a message to a session management function indicating that said protocol data unit session has been added to or removed from said downlink replication tree,
• wherein said message comprises an internet protocol address associated with a multicast destination of said internet protocol multicast flow.

A computer program product comprising at least one non-transitory computer-readable storage medium having computer-executable program code instructions stored therein, the computer-executable program code instructions comprising program code instructions configured, upon execution, to:

• cause a user plane function to report when a protocol data unit session has been added to or removed from a downlink replication tree associated with an internet protocol multicast flow;
• receive, from the user plane function, a message indicating that a protocol data unit session has been added to or removed from the downlink replication tree associated with the internet protocol multicast flow, said message comprising at least an internet protocol address associated with a multicast destination of said internet protocol multicast flow;
• and
• forward the indication that a protocol data unit session has been added to or removed from the downlink replication tree associated with the internet protocol multicast flow to entities that have been requested to be notified of such an event.