Multicast forwarding method and apparatus

A multicast forwarding method, applied to a bit index explicit replication (BIER) network, comprising:

• receiving, by a registration router, a bit-forwarding egress router (BFER) registration message from a BFER, wherein the registration router is configured to process a multicast registration message, wherein the multicast registration message comprises the BFER registration message, wherein the BFER registration message comprises information about a multicast group, wherein a destination Internet Protocol (IP) address of the BFER registration message is an IP address of the registration router, and wherein a source IP address of the BFER registration message is an IP address of the BFER;
• obtaining, by the registration router, a BFER entry according to the BFER registration message, wherein the BFER entry comprises the information about the multicast group and the IP address of the BFER, and wherein the IP address of the BFER corresponds to the information about the multicast group;
• sending, by the registration router, an advertisement packet in the BIER network, wherein the advertisement packet advertises that the registration router is configured to process the multicast registration message, and wherein the advertisement packet comprises the IP address of the registration router and the information about the multicast group;
• receiving, by the registration router, a BFER deregistration message from the BFER, wherein the BFER deregistration message comprises the IP address of the BFER and information about a deleted multicast group;
• determining, by the registration router, a to-be-deleted BFER entry according to the information about the multicast group and the IP address of the BFER, wherein the to-be-deleted BFER entry comprises the IP address of the BFER and the information about the deleted multicast group;
• and
• deleting, by the registration router, the to-be-deleted BFER entry.

A multicast forwarding method, applied to a bit index explicit replication (BIER) network, comprising:

• receiving, by a bit-forwarding ingress router (BFIR), a multicast packet from a multicast source, wherein the multicast packet comprises information about a multicast group, and wherein the BFIR is coupled to the multicast source;
• obtaining, by the BFIR from a registration router, an Internet Protocol (IP) address of a bit-forwarding egress router (BFER) corresponding to the multicast group, wherein the registration router is configured to process a multicast registration message;
• obtaining, by the BFIR, a BIER multicast packet according to the multicast packet and the IP address of the BFER, wherein the BIER multicast packet comprises a BIER header and the multicast packet, wherein the BIER header comprises a bit string, and wherein a bit, in the bit string, corresponding to the BFER is set;
• sending, by the BFIR, the BIER multicast packet to the BFER;
• and
• obtaining, by the BFIR, information about at least one registration router by receiving an advertisement packet, wherein the advertisement packet advertises that the at least one registration router is configured to process the multicast registration message, wherein the advertisement packet comprises the information about the at least one registration router, and wherein the information about the at least one registration router comprises an IP address of the at least one registration router and information about a multicast group supported by the at least one registration router, and
• wherein obtaining the IP address of the BFER corresponding to the multicast group comprises:
• sending, by the BFIR, a multicast source registration message to the registration router according to an IP address of the registration router, wherein the multicast source registration message comprises the information about the multicast group and an IP address of the BFIR, and wherein the multicast registration message comprises the multicast source registration message;
• receiving, by the BFIR, a BFER list message from the registration router, wherein the BFER list message comprises the IP address of the BFER, wherein a destination IP address of the BFER list message is the IP address of the BFIR, and wherein a source IP address of the BFER list message is the IP address of the registration router;
• and
• obtaining, by the BFIR, the IP address of the BFER from the BFER list message.

A bit-forwarding egress router (BFER), wherein the BFER is located in a bit index explicit replication (BIER) network, and wherein the BFER comprises:

• a processor configured to:
• determine, according to information about a multicast group in a multicast receiver list obtained in advance, an Internet Protocol (IP) address of a registration router that supports the multicast group, wherein the registration router is configured to process a multicast registration message;
• generate a BFER registration message according to the information about the multicast group and the IP address of the registration router, wherein the BFER registration message is part of the multicast registration message, wherein the BFER registration message comprises the information about the multicast group, wherein a destination IP address of the BFER registration message is the IP address of the registration router, and wherein a source IP address of the BFER registration message is an IP address of the BFER;
• and
• obtain a BFER deregistration message after an entry that is part of the multicast receiver list is deleted, wherein the deleted entry comprises information about a multicast group, wherein the BFER deregistration message comprises the information about the multicast group in the deleted entry and the IP address of the BFER, and
• a transmitter coupled to the processor and configured to:
• send the BFER registration message to the registration router;
• and
• send the BFER deregistration message to the registration router.

A registration router, wherein the registration router is located in a bit index explicit replication (BIER) network, wherein the registration router is configured to process a multicast registration message, and wherein the registration router comprises:

• a receiver configured to receive a bit-forwarding egress router (BFER) registration message from a BFER, wherein the multicast registration message comprises the BFER registration message, wherein the BFER registration message comprises information about a multicast group, wherein a destination Internet Protocol (IP) address of the BFER registration message is an IP address of the registration router, and wherein a source IP address of the BFER registration message is an IP address of the BFER;
• a processor coupled to the receiver and configured to obtain a BFER entry according to the BFER registration message, wherein the BFER entry comprises the information about the multicast group and the IP address of the BFER, and wherein the IP address of the BFER corresponds to the information about the multicast group;
• and
• a transmitter coupled to the receiver and the processor and configured to send an advertisement packet in the BIER network, wherein the advertisement packet advertises that the registration router is configured to process the multicast registration message, and wherein the advertisement packet comprises the IP address of the registration router and the information about the multicast group,
• wherein the receiver is further configured to receive a BFER deregistration message from the BFER, wherein the BFER deregistration message comprises the IP address of the BFER and information about a deleted multicast group, and
• wherein the processor is further configured to:
• determine a to-be-deleted BFER entry according to the information about the multicast group and the IP address of the BFER, wherein the to-be-deleted BFER entry comprises the IP address of the BFER and the information about the deleted multicast group;
• and
• delete the to-be-deleted BFER entry.

A bit-forwarding ingress router (BFIR), wherein the BFIR is located in a bit index explicit replication (BIER) network, and wherein the BFIR comprises:

• a receiver configured to receive a multicast packet from a multicast source, wherein the multicast packet comprises information about a multicast group, and wherein the BFIR is coupled to the multicast source;
• a processor coupled to the receiver and configured to:
• obtain, from a registration router, an Internet Protocol (IP) address of a bit-forwarding egress router (BFER) corresponding to the multicast group, wherein the registration router is configured to process a multicast registration message;
• obtain a BIER multicast packet according to the multicast packet and the IP address of the BFER, wherein the BIER multicast packet comprises a BIER header and the multicast packet, wherein the BIER header comprises a bit string, and wherein a bit, in the bit string, corresponding to the BFER is set;
• and
• obtain information about at least one registration router by receiving an advertisement packet, wherein the advertisement packet advertises that the at least one registration router is configured to process the multicast registration message, wherein the advertisement packet comprises the information about the at least one registration router, and wherein the information about the at least one registration router comprises an IP address of the at least one registration router and information about a multicast group supported by the at least one registration router;
• and
• a transmitter coupled to the receiver and the processor and configured to:
• send the BIER multicast packet to the BFER;
• and
• send a multicast source registration message to the registration router according to an IP address of the registration router, wherein the multicast source registration message comprises the information about the multicast group and an IP address of the BFIR, and wherein the multicast registration message comprises the multicast source registration message,
• wherein receiver is further configured to receive a BFER list message from the registration router, wherein the BFER list message comprises the IP address of the BFER, wherein a destination IP address of the BFER list message is the IP address of the BFIR, and wherein a source IP address of the BFER list message is the IP address of the registration router, and
• wherein the processor is further configured to obtain the IP address of the BFER from the BFER list message.