Quality of service for inbound network traffic flows during slow-start phases
View Patent ↗An edge network device controls the quality-of-service of incoming network traffic flows by limiting the bandwidth of incoming network traffic flows to create a network traffic bottleneck at the edge network device. The bottleneck ensures that this edge network device may control the quality-of-service of incoming network traffic flows. During a slow-start phase of a network traffic flow, the edge network device adds phantom network packets to a scheduler queue in addition to the actual packets of the network traffic flow. Phantom packets occupy transmission slots during packet scheduling and are discarded when selected for transmission. This limits the rate that actual packets are received and acknowledged by the destination knowledge, thereby preventing the network traffic flow source from increasing the flow bandwidth above the limit of the inbound network connection.
1. A method of controlling incoming network traffic to a network device, the method comprising:
receiving at least a first network packet associated with a first network traffic flow;
adding at least the first network packet to a packet scheduler queue associated with at least the first network traffic flow;
determining if the first network traffic flow is operating in a slow-start phase; and
in response to the determination that the first network traffic flow is operating in the slow-start phase, adding a phantom network packet to the packet scheduler queue.
2. The method of claim 1 , comprising
selecting at least one network packet in the packet scheduler queue in response to a network packet scheduler;
determining if the selected network packet is the phantom network packet;
in response to the determination that the selected packet is a previously queued phantom network packet, discarding the selected network packet; and
in response to the determination that the selected packet is not a previously queued network packet, directing the first network packet towards its destination.
3. The method of claim 2 , wherein the first network packet is received via a first network connection having a maximum incoming bandwidth and the network packet scheduler selects network packets from the packet scheduler queue at a maximum outgoing bandwidth less than the maximum incoming network bandwidth.
4. The method of claim 2 , wherein selecting the at least one network packet, determining if the selected network packet is the phantom network packet, and discarding or directing the selected network packet are performed asynchronously and in parallel with adding the first network packet to the packet scheduler queue.
5. The method of claim 1 , wherein adding the phantom network packet to the packet scheduler queue comprises:
inhibiting the addition of the phantom network packet to the packet scheduler queue unless at least one additional network packet has been added to the packet scheduler queue.
6. The method of claim 1 , wherein the phantom packet has a fixed and predetermined length.
7. The method of claim 1 , wherein the phantom packet has a length based on a function of at least the length of the first network packet.
8. The method of claim 1 , wherein determining if the first network traffic flow is operating in the slow-start phase comprises:
determining if any previously sent network packets associated with the first network traffic flow has been lost; and
in response to the determination that the previously sent network packets associated with the network traffic flow have not been lost, specifying that the first network traffic flow is operating in the slow-start phase.
9. The method of claim 1 , wherein determining if the first network traffic flow is operating in the slow-start phase comprises:
determining if a predetermined time period from the start of the first network traffic flow has elapsed; and
in response to the determination that the predetermined time period from the start of the first network traffic flow has not elapsed, specifying that the first network traffic flow is operating in the slow-start phase.
10. The method of claim 1 , wherein determining if the first network traffic flow is operating in the slow-start phase comprises:
determining if a time period has elapsed based on a function of at least one attribute of the first network traffic flow; and
in response to the determination that the time period has not elapsed, specifying that the first network traffic flow is operating in the slow-start phase.
11. The method of claim 10 , wherein the attribute of the first network traffic flow includes a bandwidth of the first network traffic flow.
12. The method of claim 10 , wherein the attribute of the first network traffic flow includes a round-trip time attribute of the first network traffic flow.
13. The method of claim 1 , wherein the first network traffic flow includes a TCP traffic flow.
14. A non-transitory computer-readable storage medium including instructions adapted to direct a processor to perform an operation, the operation comprising:
receiving at least a first network packet associated with a first network traffic flow;
adding at least the first network packet to a packet scheduler queue associated with at least the first network traffic flow;
determining if the first network traffic flow is operating in a slow-start phase; and
in response to the determination that the first network traffic flow is operating in the slow-start phase, adding a phantom network packet to the packet scheduler queue.
15. The non-transitory computer-readable medium of claim 14 , comprising
selecting at least one network packet in the packet scheduler queue in response to a network packet scheduler;
determining if the selected network packet is the phantom network packet;
in response to the determination that the selected packet is a previously queued phantom network packet, discarding the selected network packet; and
in response to the determination that the selected packet is not a previously queued network packet, directing the first network packet towards its destination.
16. The non-transitory computer-readable medium of claim 15 , wherein the first network packet is received via a first network connection having a maximum incoming bandwidth and the network packet scheduler selects network packets from the packet scheduler queue at a maximum outgoing bandwidth less than the maximum incoming network bandwidth.
17. The non-transitory computer-readable medium of claim 15 , wherein selecting the at least one network packet, determining if the selected network packet is the phantom network packet, and discarding or directing the selected network packet are performed asynchronously and in parallel with adding the first network packet to the packet scheduler queue.
18. The non-transitory computer-readable medium of claim 14 , wherein adding the phantom network packet to the packet scheduler queue comprises:
inhibiting the addition of the phantom network packet to the packet scheduler queue unless at least one additional network packet has been added to the packet scheduler queue.
19. The non-transitory computer-readable medium of claim 14 , wherein determining if the first network traffic flow is operating in the slow-start phase comprises:
determining if any previously sent network packets associated with the first network traffic flow has been lost; and
in response to the determination that the previously sent network packets associated with the network traffic flow have not been lost, specifying that the first network traffic flow is operating in the slow-start phase.
20. The non-transitory computer-readable medium of claim 14 , wherein determining if the first network traffic flow is operating in the slow-start phase comprises:
determining if a predetermined time period from the start of the first network traffic flow has elapsed; and
in response to the determination that the predetermined time period from the start of the first network traffic flow has not elapsed, specifying that the first network traffic flow is operating in the slow-start phase.
21. The non-transitory computer-readable medium of claim 14 , wherein the first network traffic flow includes a TCP traffic flow.