Apparatus to achieve quality of service (QOS) without requiring fabric speedup

Patent metadata

Field	Value
Publication number	US-9973437-B2
Application number	US-201615179639-A
Country	US
Kind code	B2
Filing date	Jun 10, 2016
Priority date	Jul 16, 2014
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

A device may store a credit value for each of multiple output components. The device may receive packets from a network device via an input component. The device may cause the input component to queue the packets. The device may selectively dequeue a packet from the input component, to be sent to an output component, based on whether the credit value for the output component satisfies a credit threshold. The device may send the packet to the output component based on a destination of the packet when the packet is dequeued from the input component. The device may determine a size of the packet after the packet is dequeued. The device may update the credit value for the output component based on the size of the packet. The device may output the packet to another network device via the output component.

First claim

What is claimed is:

1. A device, comprising:
one or more processors to:
store a count value for each of a plurality of output components;
add packets received from a network device to one or more input queues included in an input component;
selectively dequeue a packet from the input component, to be sent to an output component, based on whether the count value for the output component satisfies a threshold,
the packets including the packet, and
the plurality of output components including the output component;

send the packet to the output component when the packet is dequeued from the input component;
modify the packet after the packet is dequeued from the input component;
determine a change in size of the packet due to modifying the packet;
update the count value for the output component based on the change in size of the packet due to modifying the packet; and
output the packet to another network device via the output component.

2. The device of claim 1 , where the one or more processors, when selectively dequeuing the packet, are further to:
dequeue the packet based on the count value for the output component satisfying the threshold.

3. The device of claim 1 , where the one or more processors, when selectively dequeuing the packet, are further to:
prevent scheduling a dequeue of the packet based on the count value for the output component failing to satisfy the threshold.

4. The device of claim 1 , where the one or more processors, when modifying the packet, are further to:
drop, add, or change a header of the packet.

5. The device of claim 1 , where the one or more processors, when updating the count value based on the change in the size of the packet, are further to:
increase the count value if the packet is reduced in size due to modifying the packet; and
decrease the count value if the packet is increased in size due to modifying the packet.

6. The device of claim 1 , where the one or more processors are further to:
store a request value for each particular output component of the plurality of output components,
the request value indicating whether there are any pending dequeue requests for the particular output component; and

where the one or more processors, when selectively dequeuing the packet, are to:
selectively dequeue the packet from the input component based on whether the request value for the output component satisfies a request threshold and based on whether the count value for the output component satisfies the threshold.

7. The device of claim 6 , where the one or more processors are further to:
determine that none of the plurality of output components has the count value that satisfies the threshold and the request value that satisfies the request threshold; and
replenish the count value for each of the plurality of output components based on determining that none of the plurality of output components has the count value that satisfies the threshold and the request value that satisfies the request threshold.

8. A method comprising:
storing, by a device, a count value for each of a plurality of output components;
adding, by the device, packets received from a network device to one or more input queues included in an input component;
selectively dequeuing, by the device, a packet from the input component, to be sent to an output component, based on whether the count value for the output component satisfies a threshold,
the packets including the packet, and
the plurality of output components including the output component;

sending, by the device, the packet to the output component when the packet is dequeued from the input component;
modifying, by the device, the packet after the packet is dequeued from the input component;
determining, by the device, a change in size of the packet due to modifying the packet;
updating, by the device, the count value for the output component based on the change in size of the packet due to modifying the packet; and
outputting, by the device, the packet to another network device via the output component.

9. The method of claim 8 , where selectively dequeuing the packet includes:
dequeuing the packet based on the count value for the output component satisfying the threshold.

10. The method of claim 8 , where selectively dequeuing the packet includes:
preventing scheduling a dequeue of the packet based on the count value for the output component failing to satisfy the threshold.

11. The method of claim 8 , where modifying the packet includes:
drop, add, or change a header of the packet.

12. The method of claim 8 , where updating the count value based on the change in the size of the packet includes:
increasing the count value if the packet is reduced in size due to modifying the packet; and
decreasing the count value if the packet is increased in size due to modifying the packet.

13. The method of claim 8 , further comprising:
storing a request value for each particular output component of the plurality of output components,
the request value indicating whether there are any pending dequeue requests for the particular output component; and

where selectively dequeuing the packet includes:
selectively dequeuing the packet from the input component based on whether the request value for the output component satisfies a request threshold and based on whether the count value for the output component satisfies the threshold.

14. The method of claim 13 , further comprising:
determining that none of the plurality of output components has the count value that satisfies the threshold and the request value that satisfies the request threshold; and
replenishing the count value for each of the plurality of output components based on determining that none of the plurality of output components has the count value that satisfies the threshold and the request value that satisfies the request threshold.

15. A non-transitory computer-readable medium for storing instructions, the instructions comprising:
a plurality of instructions which, when executed by one or more processors, cause the one or more processors to:
store a count value for each of a plurality of output components;
add packets received from a network device to one or more input queues included in an input component;
selectively dequeue a packet from the input component, to be sent to an output component, based on whether the count value for the output component satisfies a threshold,
the packets including the packet, and
the plurality of output components including the output component;

send the packet to the output component when the packet is dequeued from the input component;
modify the packet after the packet is dequeued from the input component;
determine a change in size of the packet due to modifying the packet;
update the count value for the output component based on the change in size of the packet due to modifying the packet; and
output the packet to another network device via the output component.

16. The non-transitory computer-readable medium of claim 15 , where the plurality of instructions, that cause the one or more processors to selectively dequeuer the packet, cause the one or more processors to:
dequeue the packet based on the count value for the output component satisfying the threshold.

17. The non-transitory computer-readable medium of claim 15 , where the plurality of instructions, that cause the one or more processors to selectively dequeuer the packet, cause the one or more processors to:
prevent scheduling a dequeue of the packet based on the count val

Assignees

• Juniper Networks Inc

Inventors

• Pathakota Ravi
• Thomas Sarin
• Kundu Sudipta
• Vegesna Srihari R
• Irani Firdaus Mahiar
• Maji Kalpataru
• Jain Naveen K

Classifications

• H04W72/23

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04L47/527 Primary

  Quantum based scheduling, e.g. credit or deficit based scheduling or token bank · CPC title

• H04L41/5003

  Managing SLA; Interaction between SLA and QoS · CPC title

• H04L47/36

  by determining packet size, e.g. maximum transfer unit [MTU] · CPC title

• H04L47/365

  Dynamic adaptation of the packet size · CPC title