Automated weight calculation for packet networks

1. A method for communication, comprising:

setting respective overbooking ratios for multiple categories of data traffic;

assigning respective bandwidth allocations to a plurality of connections for transmitting the data traffic in one or more of the categories over a network;

coupling the data traffic from the connections into respective queues, such that each of the queues is associated with one or more of the connections;

computing respective weights for the queues responsively to the bandwidth allocations and to the overbooking ratios of the categories of the data traffic to be transmitted on the connections that are associated with each of the queues; and

multiplexing among the queues responsively to the respective weights so as to transmit the data traffic from the connections over a link in the network,

wherein computing the respective weights comprises computing respective weight contributions of the connections responsively to the categories of the data traffic transmitted on each of the connections, and summing the weight contributions of the connections that are associated with each of the queues, and

wherein the multiple categories comprises classes of service, each having at least one of a committed information rate (CIR) and an excess information rate (EIR) and having respective CIR and EIR overbooking ratios, and wherein assigning the respective bandwidth allocations comprises assigning each of the connections to at least one of the classes of service, and wherein computing the respective weight contributions comprises determining the weight contributions responsively to the classes of service of the connections, and

wherein computing the respective weight contributions comprises setting a respective weight contribution of each of the connections belonging to a given class of service CoS j to be α(CoS j )CIR(CoS j )+β(CoS j )EIR(CoS j ), wherein α and β are bias coefficients that are determined responsively to the CIR and EIR overbooking ratios of the given class of service.

2. The method according to claim 1 , wherein computing the respective weights comprises biasing the weights so as to favor, in determining the weights, the categories of the data traffic for which the respective overbooking ratios are relatively smaller over the categories of the data traffic for which the respective overbooking ratios are relatively greater.

3. The method according to claim 2 , wherein biasing the weights comprises weighting the bandwidth allocations in inverse proportion to the overbooking ratios in order to compute the respective weights.

4. The method according to claim 1 , wherein α and β are respectively inversely proportional to the CIR and EIR overbooking ratios of the given class of service.

5. The method according to claim 1 , wherein computing the respective weights comprises biasing the weights, responsively to the overbooking ratios, so that the CIR has a relatively greater impact on the weights than does the EIR.

6. The method according to claim 1 , wherein computing the respective weights comprises applying a non-linear mapping to the computed weights.

7. A method for communication, comprising:

setting respective overbooking ratios for multiple categories of data traffic;

assigning respective bandwidth allocations to a plurality of connections for transmitting the data traffic in one or more of the categories over a network;

coupling the data traffic from the connections into respective queues, such that each of the queues is associated with one or more of the connections;

computing respective weights for the queues responsively to the bandwidth allocations and to the overbooking ratios of the categories of the data traffic to be transmitted on the connections that are associated with each of the queues; and

multiplexing among the queues responsively to the respective weights so as to transmit the data traffic from the connections over a link in the network,

wherein computing the respective weights comprises computing respective weight contributions of the connections responsively to the categories of the data traffic transmitted on each of the connections, and summing the weight contributions of the connections that are associated with each of the queues, and

wherein the multiple categories comprises classes of service, each having at least one of a committed information rate (CIR) and an excess information rate (EIR) and having respective CIR and EIR overbooking ratios, and wherein assigning the respective bandwidth allocations comprises assigning each of the connections to at least one of the classes of service, and wherein computing the respective weight contributions comprises determining the weight contributions responsively to the classes of service of the connections, and

wherein multiplexing among the queues comprises preferentially serving a guaranteed portion of the CIR, and multiplexing a remainder of the CIR and the EIR, and wherein setting a respective weight contribution of each of the connections belonging to a given class of service CoS j to be α(CoS j )CIR(CoS j )[1−1/OVB CIR (CoS j )]+β(CoS j )EIR(CoS j ), wherein OVB CIR is the overbooking ratio of the CIR in the given class of service.

8. The method according to claim 7 , wherein α and β are respectively inversely proportional to the CIR and EIR overbooking ratios of the given class of service.

9. Apparatus for conveying data traffic over a plurality of connections on a network, each connection being configured to carry one or more categories of the data traffic, the apparatus comprising:

a multiplexer, which comprises a set of queues, each such queue being configured to receive the data traffic on one or more of the connections that are associated with the queue, and which is adapted to multiplex among the queues responsively to respective weights that are assigned to the queues so as to transmit the data traffic from the queues over a link in the network; and

a controller, which is coupled to receive a definition of respective bandwidth allocations and respective overbooking ratios of the categories of the data traffic carried by each of the connections, and which is adapted, responsively to the definition, to compute the respective weights to be assigned to the queues responsively to the bandwidth allocations and to the overbooking ratios of the categories of the data traffic carried by the connections that are associated with each of the queues,

wherein the controller is adapted to compute respective weight contributions of the connections responsively to the categories of the data traffic transmitted on each of the connections, and to sum the weight contributions of the connections that are associated with each of the queues in order to determine the respective weights to assign to the queues, and

wherein the multiple categories comprises classes of service, each having at least one of a committed information rate (CIR) and an excess information rate (EIR) and having respective CIR and EIR overbooking ratios, and wherein each of the connections is assigned to at least one of the classes of service, and wherein the controller is adapted to determine the respective weight contributions based on the classes of service of the connections, and

wherein the controller is adapted to set a respective weight contribution of each of the connections belonging to a given class of service CoS j to be α(CoS j )CIR(CoS j )+β(CoS j )EIR(CoS j ), wherein α and β are bias coefficients that are determined responsively to the CIR and EIR overbooking ratios of the given class of service.

10. The apparatus according to claim 9 , wherein the controller is adapted to bias the weights so as to favor, in computing the weights, the categories of the data traffic for which the respective overbooking ratios are relatively smaller over the categories of the data traffic for which the respective overbooking ratios are relatively greater.

11. The apparatus according to claim 10 , wherein the controller is adapted to bias the weights in inverse proportion to the respective overbooking ratios.

12. The apparatus according to claim 9 , wherein α and β are respectively inversely proportional to the CIR and EIR overbooking ratios of the given class of service.

13. The apparatus according to claim 9 , wherein the controller is adapted to bias the weights, responsively to the overbooking ratios, so that the CIR has a relatively greater impact on the weights than does the EIR.

14. The apparatus according to claim 9 , wherein the controller is adapted to apply a non-linear mapping to the computed weights.

15. Apparatus for conveying data traffic over a plurality of connections on a network, each connection being configured to carry one or more categories of the data traffic, the apparatus comprising:

a multiplexer, which comprises a set of queues, each such queue being configured to receive the data traffic on one or more of the connections that are associated with the queue, and which is adapted to multiplex among the queues responsively to respective weights that are assigned to the queues so as to transmit the data traffic from the queues over a link in the network; and

a controller, which is coupled to receive a definition of respective bandwidth allocations and respective overbooking ratios of the categories of the data traffic carried by each of the connections, and which is adapted, responsively to the definition, to compute the respective weights to be assigned to the queues responsively to the bandwidth allocations and to the overbooking ratios of the categories of the data traffic carried by the connections that are associated with each of the queues,

wherein the controller is adapted to compute respective weight contributions of the connections responsively to the categories of the data traffic transmitted on each of the connections, and to sum the weight contributions of the connections that are associated with each of the queues in order to determine the respective weights to assign to the queues, and

wherein the multiple categories comprises classes of service, each having at least one of a committed information rate (CIR) and an excess information rate (EIR) and having respective CIR and EIR overbooking ratios, and wherein each of the connections is assigned to at least one of the classes of service, and wherein the controller is adapted to determine the respective weight contributions based on the classes of service of the connections, and

wherein the multiplexer is adapted to preferentially serve a guaranteed portion of the CIR, and to multiplex a remainder of the CIR and the EIR, and

wherein the controller is adapted to set a respective weight contribution of each of the connections belonging to a given class of service CoS j to be α(CoS j )CIR(CoS j )[1−1/OVB CIR (CoS j )]+β(CoS j )EIR(CoS j ), wherein OVB CIR is the overbooking ratio of the CIR in the given class of service.

16. The apparatus according to claim 15 , wherein α and β are respectively inversely proportional to the CIR and EIR overbooking ratios of the given class of service.