Use cases

Sender Use Cases

Send data
Sends ODATA packets down the multicast tree
(System is a member of the multicast group)

Source Path State
Sender creates PGM tree by multicasting SPM messages.
(System is a member of the multicast group)

Repair Response
Sender responds to a NAK by multicasting a RDATA packet.
(System is a member of the multicast group)



Receiver Use Cases

Receive Repair Request
Receiver has identified lost data packets and unicasts NAK to system.


Network Element Use Cases

Send data
Sends ODATA packets down the multicast tree
(System is a member of the multicast group)

Source Path State
Network Element multicasts SPM messages initiated by sender to create PGM tree.
(System is a member of the multicast group)

Receive Repair Request
A Repair request has been received by the network element and is being forwarded up the PGM tree towards the sender.

NCF
Network Element multicasts confirmation of receipt of repair request on the same interface as NAK was received. System receives multicast confirmation.