Protocols for messaging between a centralized network management system and other entities are described. According to one embodiment, in response to a request of a subscriber for joining a multicast group received at a centralized aggregation server, the centralized aggregation server transmits a port subscriber announcement (PSA) message to substantially all subscriber access multiplexers over an access network. The PSA message includes an identifier (ID) of the subscriber. In response to the PSA message, a subscriber access multiplexer having a subscriber matching the ID of the subscriber in the PSA message identifies a user port corresponding to the subscriber and applies a local service policy to the identified user port. Subsequent multicast messages destined to the subscriber are delivered by the subscriber access multiplexer to the subscriber based on the local service policy corresponding to the receiving subscriber without having the aggregation server handling the service policy of the receiving subscriber. Other methods and apparatuses are also described.