Weighted bandwidth switching device

• US 20080159145A1
• Filed: 12/29/2006
• Published: 07/03/2008
• Est. Priority Date: 12/29/2006
• Status: Abandoned Application

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Muthukrishnan, Raman, Varma, Anujan
• Application Number:
  US11/647,997
• Publication Number:
  US 20080159145A1
• Time in Patent Office: Days
• US Class Current: 370/235
• CPC Class Codes: H04L 49/101 using crossbar or matrix
• CPC Class Codes: H04L 49/1523 Parallel switch fabric planes
• CPC Class Codes: H04L 49/254 Centralised controller, i.e. arbitration or scheduling
• CPC Class Codes: H04L 49/3072 Packet splitting

Abstract

In general, in one aspect, the disclosure describes an apparatus that includes a plurality of ingress modules to receive packets from external sources and to store the packets in queues based on flow. A plurality of egress modules transmit packets received from the plurality of ingress modules to external sources. A crossbar matrix provides configurable connectivity between the plurality of ingress modules and the plurality of egress modules. A scheduler receives requests for utilization of the crossbar matrix from at least a subset of the plurality of ingress modules, arbitrates amongst the requests, grants at least a subset of the requests, and configures the crossbar matrix based on the granted requests. The flows are assigned weights defining an amount of data to be transmitted during a period. When a flow meets or exceeds the assigned weight during the period the flow is deactivated from the schedule arbitration.

Claims

1. An apparatus comprising

a plurality of ingress modules to receive packets from external sources and to store the packets in queues based on flow;

a plurality of egress modules to transmit packets received from the plurality of ingress modules to external sources;

a crossbar matrix to provide configurable connectivity between the plurality of ingress modules and the plurality of egress modules; and

a scheduler to receive requests for utilization of the crossbar matrix from at least a subset of the plurality of ingress modules, to arbitrate amongst the requests, and to grant at least a subset of the requests and configure the crossbar matrix based on the granted requests, wherein the flows are assigned weights defining an amount of data to be transmitted during a period, and wherein when a flow meets or exceeds the assigned weight during the period the flow is deactivated from the schedule arbitration.

2. The apparatus of claim 1, wherein the ingress modules maintain the weights and a running count of data transmitted for their associated flows during a period and informs the scheduler when the weight for a flow is satisfied.

3. The apparatus of claim 2, wherein the ingress modules inform the scheduler in a next request.

4. The apparatus of claim 2, wherein the ingress modules maintain a satisfied flag for associated flows and set the flag for a flow when the weight for the flow is met or exceeded.

5. The apparatus of claim 4, wherein a request from an ingress module is for the associated flows and includes the satisfied flag for the associated flows.

6. The apparatus of claim 2, wherein the scheduler resets the running counts maintained by the ingress modules at the end of the period.

7. The apparatus of claim 2, wherein the scheduler can reset the running counts for a particular flow within the period.

8. The apparatus of claim 2, wherein the scheduler maintains a reset bit for the flows and activates the bit for a flow when the running counts for the flow should be reset.

9. The apparatus of claim 8, wherein a grant for an ingress module is for the associated flows and includes the reset flag for the associated flows.

10. The apparatus of claim 1, wherein if the weight for a particular flow is exceeded in a first period the excess is counted toward the weight in a second period.

11. The apparatus of claim 1, wherein the requests include parameters in addition to destination, and wherein the scheduler assigns an internal priority based on these parameters.

12. The apparatus of claim 1, wherein the ingress modules segregate received packets into segments of a first defined size and aggregate the segments into frames of a second defined size for transmission to the egress modules, and wherein the egress modules segregate the frames into segments and aggregate the segments into the packets.

13. A method comprising

receiving packets from external sources at a plurality of ingress modules;

storing the packets in queues based on flow;

sending, to a scheduler, requests for utilization of a crossbar matrix to transmit data to a plurality of egress modules;

arbitrating amongst the requests,

granting at least a subset of the requests;

configuring a crossbar matrix based on the granted requests;

maintaining weights defining an amount of data to be transmitted during a period to the flows;

tracking the amount of data transmitted for each flow during the period;

determining when a flow meets or exceeds the assigned weight during the period; and

deactivating the flow with the exceeded weight from the arbitrating.

14. The method of claim 13, wherein the ingress modules maintain, track and determine and the scheduler deactivates and further comprising informing the scheduler when the flow meets or exceeds the assigned weight.

15. The method of claim 13, further comprising determining when the tracking should be reset and resetting the tracking.

16. The method of claim 15, wherein the scheduler determines and the ingress modules reset, and further comprising informing the ingress modules to reset the tracking.

17. A store and forward device, comprising:

a plurality of interface cards, wherein the interface cards include

a plurality of ingress modules to receive packets from external sources and to store the packets in queues based on flow;

a plurality of egress modules to transmit packets received from the plurality of ingress modules to external sources;

a crossbar matrix to provide configurable connectivity between the ingress modules and the egress modules;

a scheduler to receive requests for utilization of the crossbar matrix from at least a subset of the plurality of ingress modules, to arbitrate amongst the requests, and to grant at least a subset of the requests and configure the crossbar matrix based on the granted requests, wherein the flows are assigned weights defining an amount of data to be transmitted during a period, and wherein when a flow meets or exceeds the assigned weight during the period the flow is deactivated from the schedule arbitration;

a backplane to connect the ingress modules and the egress modules to the crossbar matrix and the scheduler, and the scheduler to the crossbar matrix; and

a rack to house the interface cards, the crossbar matrix, the backplane and the scheduler.

18. The device of claim 17, wherein the ingress modules maintain the weights and a running count of data transmitted for their associated flows during a period and informs the scheduler when the weight for a flow is satisfied.

19. The device of claim 17, wherein the scheduler determines when the running counts should be reset and informs the ingress modules, and the ingress modules reset the running counts.

20. The device of claim 17, wherein the ingress modules segregate received packets into segments of a first defined size and aggregate the segments into frames of a second defined size for transmission to the egress modules, and wherein the egress modules segregate the frames into segments and aggregate the segments into the packets.