Hosts Joining a Multicast Group on a BIERv6 Network

When a host connected to a BFER requests to join a multicast group for the first time, the BFER needs to be dynamically added to the multicast group. For example, if a terminal user requests to watch an IPTV channel but the BFER corresponding to this user does not have the channel's traffic, the BFER needs to be added to a multicast group corresponding to the channel. On a BIERv6 network, the process for a host to join a multicast group does not require hop-by-hop negotiation and is transparent to transit nodes.

Figure 1 shows the process for a host to join a multicast group.

Figure 1 Process for a host to join a multicast group

The detailed process is as follows:

1. The receive end (host) sends a message (such as an IGMP Report message) to the connected BFER, requesting to join the multicast group corresponding to a multicast service.
2. The BFER sends a Join message to the BFIR.
3. After receiving the Join message, the BFIR sets the bit position of the BFER in the BitString to 1.
4. Upon receipt of a multicast packet, each BFR replicates the packet and sends a packet copy to the next hop based on the new BitString until the BFER receives the multicast packet.