Method and router in a packet network with priority classes
First Claim
1. A method of routing packets in a router of a packet network, the method comprising:
- defining several priority classes for the packets;
defining a first propagation delay threshold value and a second, higher, propagation delay threshold value for each of the several priority classes;
selecting from each of the priority classes, an oldest packet;
determining an estimate of a propagation delay of at least one of the packets;
lowering a priority of at least one packet, if the estimate of the propagation delay associated with that at least one packet is higher than the second threshold value of a present priority class associated with that at least one packet;
transmitting at least one packet of the present priority class if the estimate of the propagation delay associated with that at least one packet is higher than the first threshold value but lower than the second threshold value of the present priority class; and
selecting a next priority class;
wherein the first threshold value equals an average propagation delay determined for the priority class minus an estimated propagation delay of the packet in other parts of the network, and the second threshold value is a maximum propagation delay defined for the priority class, wherein the maximum propagation delay is based on a delay that a majority of the packets has to fall short of minus the estimated propagation delay of the packet in other parts of the network.
1 Assignment
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Accused Products
Abstract
A method and an equipment for packet prioritization when routing data packets is presented. Several priority classes are defined for the packets, and a first threshold value and a second, higher, threshold value is defined for each prioity class. In association with each packet, the oldest packet of a given prioritiy class is selected, and if the packet is older than the second threshold value of the priority class concerned, the packet is discarded, and the next priority class is selected. If the packet is older than the first threshold value of the priority class concerned, at least one packet of this priority class is transmitted until the oldest packet in the priority class is younger than the first threshold value of the priority class concerned, whereupon the next priority class is selected.
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Citations
17 Claims
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1. A method of routing packets in a router of a packet network, the method comprising:
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defining several priority classes for the packets;
defining a first propagation delay threshold value and a second, higher, propagation delay threshold value for each of the several priority classes;
selecting from each of the priority classes, an oldest packet;
determining an estimate of a propagation delay of at least one of the packets;
lowering a priority of at least one packet, if the estimate of the propagation delay associated with that at least one packet is higher than the second threshold value of a present priority class associated with that at least one packet;
transmitting at least one packet of the present priority class if the estimate of the propagation delay associated with that at least one packet is higher than the first threshold value but lower than the second threshold value of the present priority class; and
selecting a next priority class;
wherein the first threshold value equals an average propagation delay determined for the priority class minus an estimated propagation delay of the packet in other parts of the network, and the second threshold value is a maximum propagation delay defined for the priority class, wherein the maximum propagation delay is based on a delay that a majority of the packets has to fall short of minus the estimated propagation delay of the packet in other parts of the network. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A router in a packet network, the router comprising:
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means for receiving and transmitting a plurality of packets;
means for assigning a priority class to each of the plurality of packets in such a way that a first threshold value and a second, higher, threshold value is associated with each priority class;
means for selecting an oldest packet from each priority class;
means for determining an estimate of a propagation delay corresponding to at least one packet in a present priority class;
means for lowering a priority of at least one packet if the estimate of the propagation delay of that at least one packet is higher than the second threshold value of the present priority class;
means for selecting at least one packet if the estimate of the propagation delay is higher than the first threshold value of the present priority class, but lower than the second threshold value of the present priority class; and
means for selecting a next priority class.
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10. A router in a packet network, the router comprising:
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means for defining several priority classes for the packets;
means for defining a first propagation delay threshold value and a second, higher, propagation delay threshold value for each of the several priority classes;
means for selecting from each of the priority classes, an oldest packet;
means for determining an estimate of a propagation delay of at least one of the packets;
means for lowering a priority of at least one packet, if the estimate of the propagation delay associated with that at least one packet is higher than the second threshold value of a present priority class associated with that at least one packet;
means for transmitting at least one packet of the present priority class if the estimate of the propagation delay associated with that at least one packet is higher than the first threshold value but lower than the second threshold value of the present priority class; and
means for selecting a next priority class;
wherein the first threshold value equals an average propagation delay determined for the priority class minus an estimated propagation delay of the packet in other parts of the network, and the second threshold value is a maximum propagation delay defined for the priority class, wherein the maximum propagation delay is based on a delay that a majority of the packets has to fall short of minus the estimated propagation delay of the packet in other parts of the network. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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Specification