Subscribing to an IP Multicast-based Service
Source begins to send traffic
- IGMP procedure to notify the directly-attached router (DR)
- DR to send a Register message to a Rendezvous Point router in the network
DR routers to query the directly-attached hosts
- About the current multicast groups there are aware of
- To let receivers know of the active sources, hence a possible subscription
- If there are hosts that are interested in joining the group, DR routers to send Join messages towards the RP router or the router directly attached to the source
- A new branch of the multicast distribution tree is created
Multicast service subscription is *receiver*-initiated
- A source has no knowledge of the receivers