Trunking in a matrix
View Patent ↗A multistage switch includes a matrix of coupled switch devices. A logical link comprising a plurality of physical links couples a destination through the plurality of physical links to a plurality of ports in the multistage switch. Each switch device performs trunk aware forwarding to reduce the forwarding of received frames through the matrix of coupled switch devices to the destination in order to reduce unnecessary traffic in the multistage switch.
1. An apparatus comprising:
a plurality of external ports;
a plurality of devices organized into a plurality rows, each of the rows including a first fan-in/fan-out device, a second fan-in/fan-out device, and one or more switch devices, wherein:
each device in a row is associated with a different respective stage of a plurality of stages;
certain of the devices in a row are connected to each other through internal output ports;
the first and second fan-in/fan-out devices are coupled to a number of the plurality of external ports and are configured to receive data frames, each of the data frames being associated with a logical link implemented in the apparatus; and
the data frames are communicated on physical paths between one or more of the plurality of devices based on a forward vector determined based on a trunk member vector, a physical forward vector, and an echo suppression vector.
2. The apparatus as claimed in claim 1 wherein each of the one or more switch devices is configured to store a respective physical forward vector table.
3. The apparatus as claimed in claim 2 wherein the physical forward vector table includes a table select field.
4. The apparatus as claimed in claim 3 wherein the table select field determines selection of one of associated trunk tables dependent on a destination address in a received frame.
5. The apparatus as claimed in claim 3 wherein the physical forward vector table includes a bit value for each internal output port.
6. The apparatus as claimed in claim 5 wherein the bit value determines whether the data frames can be forwarded through an internal output port of the internal output ports.
7. The apparatus as claimed in claim 1 wherein each of the one or more switch devices includes a respective flow hash logic to index a flow hash when a data frame is received dependent on a destination address and a source address included in the data frame.
8. The apparatus as claimed in claim 1 wherein a data frame of the data frames is associated with a destination address, the destination address being included in a header corresponding to the data frame.
9. The apparatus as claimed in claim 1 wherein at least one of the plurality of devices is configured to store a respective echo suppression table.
10. The apparatus as claimed in claim 9 wherein each respective echo suppression table includes group membership information for an associated trunk.
11. The apparatus as claimed in claim 9 wherein each respective echo suppression table includes a bit value for each internal output port.
12. The apparatus as claimed in claim 11 wherein the bit value determines whether the data frames can be forwarded through an internal output port of the internal output ports.
13. The apparatus as claimed in claim 1 wherein a data frame of the data frames includes an IP network layer header.
14. The apparatus as claimed in claim 1 wherein the forward vector is computed by each of the one or more switch devices.
15. The apparatus as claimed in claim 1 wherein the forward vector selects an internal output port of the internal output ports through which the data frames can be forwarded to a destination.
16. The apparatus as claimed in claim 1 wherein the trunk member vector selects an internal output port of the internal output ports for forwarding data frames having same destination and source addresses to a destination.
17. The apparatus as claimed in claim 1 wherein the physical forward vector selects an internal output port of the internal output ports for forwarding the data frames.
18. The apparatus as claimed in claim 1 wherein the echo suppression vector reduces available internal output ports of the internal output ports by ensuring that a data frame is not forwarded through an internal output port at which the data frame was received.
19. A network comprising:
a multistage switch including:
i) a plurality of external ports, a first number of the plurality of external ports configured to be coupled to a source of frames;
ii) a plurality of devices organized into a plurality rows, each of the rows including a first fan-in/fan-out device, a second fan-in/fan-out device, and one or more switch devices, wherein:
each device in a row is associated with a different respective stage of a plurality of stages;
certain of the devices in a row are connected to each other through internal output ports;
the first and second fan-in/fan-out devices are coupled to a number of the plurality of external ports and are configured to receive data frames, each of the data frames being associated with a logical link implemented in the apparatus; and
the data frames are communicated on physical paths between one or more of the plurality of devices based on a forward vector determined based on a trunk member vector, a physical forward vector, and an echo suppression vector; and
a host coupled to a second number of the plurality of external ports of the multistage switch, the host being either a computer, another multistage switch or a router.
20. The network as claimed in claim 19 wherein each of the one or more switch devices is configured to store a respective physical forward vector table.
21. The network as claimed in claim 20 wherein the physical forward vector table includes a table select field.
22. The network as claimed in claim 21 wherein the table select field determines selection of one of associated trunk tables dependent on a destination address in a received frame.
23. The network as claimed in claim 19 wherein each of the one or more switch devices includes a respective flow hash logic to index a flow hash when a data frame is received dependent on a destination address and a source address included in the data frame.
24. The network as claimed in claim 19 wherein a data frame of the data frames is associated with a destination address, the destination address being included in a header corresponding to the data frame.
25. The network as claimed in claim 19 wherein a number of the plurality of devices are each configured to store a respective echo suppression table.
26. The network as claimed in claim 25 wherein each respective echo suppression table includes group membership information for an associated trunk.
27. The network as claimed in claim 19 wherein a data frame of the data frames includes an IP network layer header.