Traffic management and flow prioritization on a routed computer network
AssigneeCisco Technology, Inc.
InventorBruce Davie
Life of this patent
Estimating the term…
Abstract
Traffic shaping is combined with per-flow fairness in routing devices operating on virtual circuit (VC) networks. In the case of a backlogged VC, flows are temporarily suppressed notwithstanding their transmission priority. This suppression, however, is implemented in a manner that respects the priority level associated with the VC. In other words, although traffic is limited to backlogged VCs in order to allow those lines to clear, this limitation occurs in a manner consistent with weighting or other per-flow fairness criteria.
Claims26
A routing device configured for management of packet flows, the device comprising:
- a. at least one input port for receiving flows;
- b. at least one output port for transmitting flows on at least two virtual circuits;
- c. traffic-management means for (i) defining parameters governing transmission of packets over the virtual circuits and (ii) monitoring transmission of packets over the virtual circuits for conformance to the transmission parameters;
- d. prioritization means for (i) queueing packets arriving over an input port for transmission over an output port and (ii) selecting queued packets for transmission based on a selection criterion, the prioritization means interacting with the traffic-management means and postponing, for a selected time, transmission of selected packets where such transmission would violate the transmission parameters;
- and
- e. the selected time is selected in response to the priority level associated with the packet.
A routing device configured for management of packet flows, the device comprising:
- a. at least one input port for receiving flows;
- b. at least two output ports for transmitting flows, each port having a maximum rate of packet transmission, the maximum rates varying among the at least two output ports;
- and
- c. prioritization means for (i) queueing packets arriving over an input port for transmission over a designated output port and (ii) selecting queued packets for transmission based on a selection criterion, the selection criterion being determined by a weighted fair queueing scheme, the prioritization means associating different packets with different priority levels and selecting packets for transmission in accordance with the priority levels, the prioritization means interacting with the ports and postponing transmission of selected packets where such transmission would exceed the maximum rate of the designated output port, the prioritization means postponing selection of a packet by an amount of time proportional to the priority level associated with the packet.
A routing device configured for management of packet flows, the device comprising:
- a. at least one input port for receiving flows;
- b. at least two output ports for transmitting flows, each port having a maximum rate of packet transmission;
- and
- c. prioritization means for (i) queueing packets arriving over an input port for transmission over a designated output port and (ii) selecting queued packets for transmission based on a selection criterion, the prioritization means interacting with the ports and postponing transmission of selected packets where such transmission would exceed the maximum rate of the designated output port, the prioritization means, upon selecting a packet for transmission, interrogating the port for a violation signal, the port providing the violation signal if transmission of the selected packet would exceed the maximum transmission rate associated with the port.
A network interface for use with a router having at least one output line, the network interface comprising:
- a. means for transmitting to a plurality of virtual circuits, over an output line, packet flows received from the router;
- b. traffic-management means for (i) defining parameters governing transmission of packets and (ii) monitoring transmission of packets for conformance to the transmission parameters;
- c. prioritization means for (i) queueing packets for transmission and (ii) selecting queued packets for transmission based on a selection criterion, the prioritization means interacting with the traffic-management means and postponing, for a selected time, transmission of selected packets where such transmission would violate the transmission parameters;
- and
- d. the selected time is selected in response to the priority level associated with the packet.
A method of managing packet flows in a computer network, the method comprising the steps of:
- a. receiving packet flows from a portion of the computer network for transmission to another portion of the computer network over a plurality of virtual circuits;
- b. defining parameters governing transmission of packets;
- c. monitoring transmission of packets for conformance to the transmission parameters;
- d. queueing packets for transmission;
- e. selecting queued packets for transmission based on a selection criterion but postponing, for a selected time, transmission of selected packets where such transmission would violate the transmission parameters;
- and
- f. the selected time is selected in response to the priority level associated with the packet.
Dependencies are inferred from the claim text.