Encoding-based multicast packet duplication control suitable for VLAN systems
View Patent ↗A packet duplication control system including an input port for receiving a packet and a plurality of output ports for outputting duplications of the packet is disclosed. The duplications can be suitable to support a Virtual Local Area Network (VLAN) system. The duplications can be controlled by descriptors arranged in a linked-list table. Also, the descriptors can have encoding formats, such as contiguous range encoding, non-contiguous range encoding, and discrete encoding. Further, the linked-list table can include at least one shared descriptor.
1. A multicast packet duplication system, comprising:
an input port configured to receive a multicast packet including multicast address data;
a pointer table including a plurality of pointers that are selectable based upon the multicast address data, each pointer from among the plurality of pointers including a plurality of entries;
a linked-list table including a plurality of multicast descriptors that are identifiable by a corresponding entry from among the plurality of entries; and
a plurality of output ports configured to output a plurality of duplicates of the multicast packet based upon an identified multicast descriptor from among the plurality of multicast descriptors,
the plurality of duplicates being distributed on a per port basis on at least one of the plurality of the output ports based upon the identified multicast descriptor, rather than by distributing the packet on all of the plurality of output ports;
wherein at least one of the plurality of multicast descriptors is shared among multiple output ports from among the plurality of output ports.
2. The multicast packet duplication system of claim 1 , wherein the plurality of multicast descriptors include a multicast packet time to live field.
3. A multicast packet duplication system, comprising:
an input port configured to receive a multicast packet including multicast address data;
a pointer table including a plurality of pointers that are selectable based upon the multicast address data, each pointer from among the plurality of pointers including a plurality of entries;
a linked-list table including one or more multicast Virtual Local Area Network (VLAN) descriptors that are identifiable by a corresponding entry from among the plurality of entries; and
a plurality of output ports, coupled to one or more VLANs, configured to output a plurality of duplicates of the multicast packet to the one or more VLANs based upon an identified VLAN multicast descriptor from among the one or more multicast VLAN descriptors,
the plurality of duplicates being distributed on a per port basis on at least one of the plurality of the output ports based upon the identified VLAN multicast descriptor, rather than by distributing the multicast packet on all of the plurality of output ports;
wherein at least one of the one or more multicast VLAN descriptors is shared among multiple output ports of the plurality of output ports.
4. The multicast packet duplication system of claim 1 , wherein some of the plurality of multicast descriptors are configured or programmed for:
duplicating a first Lumber of the plurality of duplicates of the multicast packet on a first output port from among the plurality of output ports; and
duplicating a second number of the plurality of duplicates of the multicast packet on a second output port from among the plurality of output ports, the first number being different from the second number.
5. The multicast packet duplication system of claim 3 , wherein some of the one or more multicast VLAN descriptors are configured or programmed for:
duplicating a first number of the plurality of duplicates of the multicast packet on a first output port from among the plurality of output ports; and
duplicating a second number of the plurality of duplicates of the multicast packet on a second output port from among the plurality of output ports, the first number being different from the second number.
6. The multicast packet duplication system of claim 1 , further comprising:
a multicast table comprising a plurality of second pointers,
wherein each pointer from among plurality of second pointers is used to select a corresponding pointer from among the plurality of pointers.
7. The multicast packet duplication system of claim 1 , wherein the plurality of output ports is coupled to one or more Virtual Local Area Networks (VLANs).
8. The multicast packet duplication system of claim 7 , wherein the plurality of entries includes a plurality of second pointers to identify a corresponding multicast descriptor from among the plurality of multicast descriptors.
9. The multicast packet duplication system of claim 7 , wherein the plurality of multicast descriptors comprise a plurality of multicast VLAN descriptors.
10. The multicast packet duplication system of claim 9 , wherein an encoding format of the plurality of multicast VLAN descriptors comprises at least one of:
a contiguous range encoding that includes a starting VLAN indicator and an ending VLAN indicator for a first set of multicast VLAN descriptors from among the plurality of multicast VLAN descriptors within the contiguous range;
a non-contiguous range encoding that includes information or data of a most significant bit (MSB) portion of a VLAN indicator; and
a discrete encoding that includes a first VLAN indicator and a second VLAN indicator.
11. The multicast packet duplication system of claim 3 , wherein the plurality of entries include a corresponding second pointer from among a plurality of second pointers that corresponds to at least one of the one or more multicast VLAN descriptors.
12. The multicast packet duplication system of claim 3 , further comprising:
a multicast table comprising a plurality of second pointers,
wherein each pointer from among the plurality of second pointers links to a corresponding pointer from among the plurality of pointers.
13. The multicast packet duplication system of claim 3 , wherein an encoding format of the one or more multicast VLAN descriptors includes at least one of:
a contiguous range encoding that includes a starting VLAN indicator and an ending VLAN indicator for a first set of multicast VLAN descriptors or the one or more multicast VLAN descriptors within the contiguous range;
a non-contiguous range encoding that includes information or data of a most significant bit (MSB) portion of a VLAN indicator; and
a discrete encoding that includes a first VLAN indicator and a second VLAN indicator.
14. A multicast packet duplication system, comprising:
an input port configured to receive a multicast packet comprising multicast address data;
a memory including:
a multicast table including a plurality of first pointers that are selectable based upon the multicast address data, each first pointer from among the plurality of first pointers including a multicast descriptor,
a multicast Virtual Local Area Network (VLAN) table including a plurality of second pointers that are selectable based upon a corresponding multicast descriptor of a corresponding first pointer from among the plurality of first pointers, each second pointer from among the plurality of second pointers including a plurality of entries, and
a VLAN linked-list table including a plurality of multicast VLAN descriptors that are identifiable by a corresponding entry from among the plurality of entries of a corresponding second pointer from among the plurality of second pointers; and
a plurality of output ports configured to receive a plurality of duplicates of the multicast packet on a per port basis at only those output ports designated in an identified multicast VLAN descriptor from among the plurality of multicast VLAN descriptors.
15. The multicast packet duplication system of claim 14 , wherein some of the multicast VLAN descriptors are configured or programmed for:
duplicating a first number of the plurality of duplicates on a first output port from among the plurality of output ports; and
duplicating a second number of the plurality of duplicates on a second output port from among the plurality of output ports, the first number being different from the second number.
16. The multicast packet duplication system of claim 14 , wherein the plurality of entries include pointers to a corresponding multicast VLAN descriptor from among the plurality of multicast VLAN descriptors.
17. The multicast packet duplication system of claim 14 , wherein the multicast descriptor includes a multicast packet time to live field.
18. The multicast packet duplication system of claim 14 , wherein each of the plurality of entries describes the multicast packet distribution to a different VLAN.
19. The multicast packet duplication system of claim 14 , wherein at least one of the multicast VLAN descriptors is shared among multiple output ports of the plurality of output ports.
20. The multicast packet duplication system of claim 9 , wherein the multicast VLAN descriptors include a plurality of entries, each entry from among the plurality of entries describing the multicast packet distribution to a different VLAN.