SPB Based Multicast Forwarding Method and SPBM Bridge

A first Shortest Path Bridging MAC (SPBM) bridge, applied to Shortest Path Bridging (SPB) based multicast forwarding, comprising:

• a configuring unit to run a Shortest Path Source Identification (SPSourceID) allocation protocol to preallocate multiple SPSourceIDs to the first SPBM bridge;
• a determining unit to determine that the first SPBM bridge is a SPBM bridge connected to an Internet Protocol (IP) multicast source of an IP multicast group;
• a selecting and generating unit to, when the determining unit determines that the first SPBM bridge is a SPBM bridge connected to the IP multicast source, select a SPSourceID for the IP multicast group from the multiple SPSourceIDs preallocated by the configuring unit, and generate a SPBM multicast group address of the IP multicast group according to the selected SPSourceID;
• and
• a receiving and sending unit to:
• send other SPBM bridges a first SPB-Intermediate System to Intermediate System (ISIS) Link Status Packet (LSP) that contains the selected SPSourceID and a first multicast identity indicating that the first SPBM bridge is connected to the IP multicast source;
• when receiving a second SPB-ISIS LSP that contains a second multicast identity indicating that a second SPBM bridge sending the second SPB-ISIS LSP is connected to an IP multicast member of the IP multicast group, configure the first SPBM bridge's interface connected to the IP multicast member as an egress of a SPBM multicast group;
• and
• when receiving an IP multicast packet sent by the IP multicast source, encapsulate the IP multicast packet into a SPBM multicast frame according to the SPBM multicast group address, and forward the SPBM multicast frame through the egress.

A first Shortest Path Bridging MAC (SPBM) bridge, applied to Shortest Path Bridging (SPB) based multicast forwarding, comprising:

• a determining unit to determine that the first SPBM bridge is a SPBM bridge connected to an Internet Protocol (IP) multicast member of an IP multicast group;
• and
• a receiving and sending unit to:
• when the determining unit determines that the first SPBM bridge is a SPBM bridge connected to the IP multicast member, send other SPBM bridges a first SPB-ISIS LSP that contains a first multicast identity indicating that the first SPBM bridge is connected to the IP multicast member;
• when receiving a second SPB-Intermediate System to Intermediate System (ISIS) Link Status Packet (LSP) that contains a Shortest Path Source Identification (SPSourceID) and a second multicast identity indicating that a second SPBM bridge sending the second SPB-ISIS LSP is connected to an IP multicast source of the IP multicast group, generate a SPBM multicast group address according to the SPSourceID contained in the second SPB-ISIS LSP, and configure the first SPBM bridge's interface connected to the IP multicast source as an ingress of a SPBM multicast group;
• and
• when receiving a SPBM multicast frame through the ingress of the SPBM multicast group, decapsulate the SPBM multicast frame into an IP multicast packet, and forward the IP multicast packet to the IP multicast member.

A first Shortest Path Bridging MAC (SPBM) bridge, applied to Shortest Path Bridging (SPB) based multicast forwarding, comprising:

• a determining unit to determine that the first SPBM bridge is a SPBM bridge that is neither connected to an IP multicast source nor an IP multicast member of an IP multicast group;
• and
• a receiving and sending unit to:
• when the determining unit determines that the first SPBM bridge is a SPBM bridge that is neither connected to the IP multicast source nor the IP multicast member, and receives a first SPB-Intermediate System to Intermediate System (ISIS) Link Status Packet (LSP) that contains a Shortest Path Source Identification (SPSourceID) and a first multicast identity indicating that a second SPBM bridge is connected to the multicast source, generate a SPBM multicast group address according to the SPSourceID contained in the first SPB-ISIS LSP;
• perform SPT calculation, and, when determining that the first SPBM bridge is a node in a SPT, configure the first SPBM bridge's interface connected to the IP multicast source as an ingress of a SPBM multicast group;
• when receiving a second SPB-ISIS LSP that contains a multicast identity indicating that a third SPBM bridge sending the second SPB-ISIS LSP is connected to the IP multicast member:
• perform SPT calculation, and, when determining that the first SPBM bridge is a node in another SPT, configure the first SPBM bridge's interface connected to the IP multicast source as an egress of the SPBM multicast group;
• and
• when receiving an SPBM multicast frame from the ingress, forward the SPBM multicast frame through the egress;
• and
• wherein the determining unit is to perform a multicast monitoring process, and, when the determining unit does not learn that a local Ethernet port of the first SPBM bridge is a port of the IP multicast member of the IP multicast group and that the local Ethernet port is a port of a multicast router of the IP multicast group, determine that the first SPBM bridge is a SPBM bridge that is neither connected to the IP multicast source nor the IP multicast member.