Intra switch transport protocol

• US 9,628,406 B2
• Filed: 03/13/2013
• Issued: 04/18/2017
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Morandin, Guglielmo, Singh, Sushil, Chang, Jonathan, Huber, John
• Primary Examiner(s): Hsu, Alpus H
• Application Number:
  US13/798,724
• Publication Number:
  US 20140269294A1
• Time in Patent Office: 1,497 Days
• CPC Class Codes: H04L 47/225 Determination of shaping rate, e.g. using a moving window
• CPC Class Codes: H04L 47/27 Evaluation or update of window size, e.g. using information derived from acknowledged [ACK] packets
• CPC Class Codes: H04L 47/283 in response to processing delays, e.g. caused by jitter or round trip time [RTT]
• CPC Class Codes: H04L 47/826 Involving periods of time
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]

Abstract

In one implementation, a network device is configured to implement an intra switch transport protocol. The intra switch transport protocol is configured to determine a window size according to a predetermined bandwidth and a round trip time between a plurality of ingress ports and an egress port. The network device is configured to sending at least one data packet from an ingress port to an egress port without first receiving any acknowledgement from the egress port. The network device continues to send packets and increment a counter accordingly until the counter reaches the window size. The network device ceases transmission of subsequent data packets and/or queues subsequent data packets based on the counter exceeding the window size.

Claims

1. A method for operation of a crossbar switch including an egress device and a plurality of ingress devices, the method comprising:

calculating, at the egress device, a maximum window size according to a bandwidth delay product, wherein the bandwidth delay product is calculated based on a bandwidth and a round trip time between the ingress device sending the data packet and the egress device;

assigning an egress default window value sequentially to the plurality of ingress devices;

identifying when the maximum window size has been fully allocated in the assigned egress default window values;

calculating, in response to receipt of a data packet sent from one of the plurality of ingress devices assigned the egress default window value, an assigned window value for the one ingress device sending the data packet based on an average window currently allocated to the plurality of ingress devices assigned the egress default window value; and

assigning a smaller window value subsequently to one of the plurality of ingress devices not previously assigned a window value, when the one ingress device not previously assigned a window value requests to send a data packet, wherein the smaller window value is less than the egress default window value.

2. The method of claim 1, wherein the bandwidth is associated with the egress device.

3. The method of claim 2, wherein the round trip time corresponds to a time from when the data packet leaves the ingress device until an acknowledgment message is received.

4. The method of claim 1, wherein the egress default window size is calculated from dividing the maximum window size by a number of the plurality of ingress devices.

5. The method of claim 1, wherein the egress default window size is a predetermined percentage of the bandwidth delay product.

6. The method of claim 1, wherein the assigned window value is assigned based on a priority class of the data packet.

7. The method of claim 1, wherein the crossbar switch connects the plurality of ingress devices to the egress device.

8. An apparatus for operating a crossbar switch including an egress device and a plurality of ingress devices comprising:

a controller configured to;

calculate, at the egress device, a maximum window size according to a bandwidth delay product calculated based on a bandwidth and a round trip time between the ingress device sending the data packet and the egress device;

assign an egress default window value to the plurality of ingress devices;

identify when the maximum window size has been fully allocated in the assigned egress default window values;

calculate, in response to receipt of a data packet sent from one of the plurality of ingress devices assigned the egress default window value, an assigned window value for the one ingress device sending the data packet based on the average window currently allocated to the plurality of ingress devices assigned the egress default window value; and

assign a smaller window value subsequently to one of the plurality of ingress devices not previously assigned a window value when the one ingress device not previously assigned a window value requests to send a data packet.

9. The apparatus of claim 8, wherein the round trip time corresponds to a time from when the data packet leaves the ingress device until an acknowledgment message is received.

10. The apparatus of claim 8, wherein the egress default window size is calculated from dividing the maximum window size by a number of the plurality of ingress devices.

11. The apparatus of claim 8, wherein the egress default window size is a predetermined percentage of the bandwidth delay product.

12. The apparatus of claim 8, wherein the assigned window value is assigned based on a priority class of the data packet.

13. The apparatus of claim 8, wherein the crossbar switch connects the plurality of ingress devices to the egress device.

14. A non-transitory computer readable medium including instructions that when executed are operable to:

calculate, at an egress device, a maximum window size according to a bandwidth delay product calculated based on a bandwidth and a round trip time between the ingress device sending the data packet and the egress device;

assign an egress default window value to a plurality of ingress devices;

identify when the maximum window size has been fully allocated in the assigned egress default window values;

calculate, in response to receipt of a data packet sent from one of the plurality of ingress devices assigned the egress default window value, an assigned window value for the one ingress device sending the data packet based on the average window currently allocated to the plurality of ingress devices assigned the egress default window value; and

assign a smaller window value subsequently to one of the plurality of ingress devices not previously assigned a window value, when the one ingress device not previously assigned a window value requests to send a data packet, wherein the smaller window value is less than the egress default window value.

15. The non-transitory computer readable medium of claim 14, wherein the round trip time corresponds to a time from when the data packet leaves the ingress device until an acknowledgment message is received.

16. The non-transitory computer readable medium of claim 14, wherein the egress default window size is calculated from dividing the maximum window size by a number of the plurality of ingress devices.

17. The non-transitory computer readable medium of claim 14, wherein the egress default window size is a predetermined percentage of the bandwidth delay product.

18. The non-transitory computer readable medium of claim 14, wherein the assigned window value is assigned based on a priority class of the data packet.