Explicit block encoding of multicast group membership information with bit index explicit replication (BIER)

A non-transitory machine readable storage medium having stored therein instructions to be executed by a network device to forward a packet that is encoded using an explicit block encoding of multicast group membership information with Bit Index Explicit Replication (BIER), the instructions when executed by the network device cause the network device to perform a set of operations comprising:

• receiving a packet, wherein the packet includes a bitstring having a set of blocks, each block including a set identifier (SI) field and a SubBitString field;
• selecting an unprocessed block from the set of blocks for processing;
• finding a first bit position of a SubBitString of the selected block, wherein the first bit position identifies a destination bit-forwarding router (BFR);
• looking up a forwarding bitmask for the destination BFR and a next-hop neighbor to reach the destination BFR in a bit index forwarding table (BIFT);
• creating a copy of the packet;
• applying a bit-wise AND operation on a bitstring of the copy of the packet with the forwarding bitmask;
• forwarding the copy of the packet to the next-hop neighbor;
• and
• applying a bit-wise AND operation on the bitstring of the packet with an inverse of the forwarding bitmask.

A computing device implementing a plurality of virtual machines for implementing network function virtualization (NFV), wherein a virtual machine from the plurality of virtual machines is configured to forward a packet that is encoded using an explicit block encoding of multicast group membership information with Bit Index Explicit Replication (BIER), the computing device comprising:

• a storage medium to store a BIER module;
• and
• a processor communicatively coupled to the storage medium, the processor configured to execute the virtual machine, where the virtual machine is configured to implement the BIER module, the BIER module configured to receive a packet that includes a bitstring having a set of blocks, each block including a set identifier (SI) field and a SubBitString field, select an unprocessed block from the set of blocks for processing, find a first bit position of a SubBitString of the selected block, where the first bit position identifies a destination bit-forwarding router (BFR), look up a forwarding bitmask for the destination BFR and a next-hop neighbor to reach the destination BFR in a bit index forwarding table (BIFT), create a copy of the packet, apply a bit-wise AND operation on a bitstring of the copy of the packet with the forwarding bitmask, forward the copy of the packet to the next-hop neighbor, and apply a bit-wise AND operation on the bitstring of the packet with an inverse of the forwarding bitmask.