Allocating bandwidth in a resilient packet ring network by P controller
View Patent ↗Implementations and techniques for allocating bandwidth in a resilient packet ring network by a P-type controller are generally disclosed.
1. A method implemented in a resilient packet ring network, comprising:
measuring a current transit queue length;
determining a fair rate to facilitate an allocated bandwidth in the resilient packet ring network via a P-type controller associated with at least one node of the resilient packet ring network, wherein determining the fair rate comprises determining a difference between a target queue length and the current transit queue length; and
stabilizing one or more forwarding rates associated with the at least one node of the resilient packet ring network under unbalanced traffic scenarios, based at least in part on the allocated bandwidth,
wherein the fair rate F(n) is expressed as:
F ( n )= F ( n− 1)− k p ( e ( n )− e ( n− 1))
where F(n−1) is a prior fair rate, where K p is a proportional gain, where e(n) is the difference between the target queue length and the current transit queue length, and where e(n−1) is a prior difference between the target queue length and the current transit queue length.
2. The method of claim 1 , wherein determining the fair rate comprises determining rate of change of the difference between the target queue length and the current transit queue length.
3. The method of claim 1 , wherein determining the fair rate comprises determining a round trip delay between a bottleneck link of the resilient packet ring network and the at least one node of the resilient packet ring network.
4. The method of claim 1 , wherein the determination of a fair rate is based at least in part on a proportional gain k p expressed as:
0
<
k
p
<
π
2
W
τ
where W is a sum of weights associated with nodes of the resilient packet ring network, and where τ is based at least in part on a round trip delay between a bottleneck link of the resilient packet ring network and the at least one node of the resilient packet ring network.
5. An article for use with a resilient packet network, comprising:
a non-transitory signal bearing medium comprising machine-readable instructions stored thereon, which, if executed by one or more processors, operatively enable a computing device to:
measure a current transit queue length;
determine a fair rate to facilitate an allocated bandwidth in the resilient packet ring network via a P-type controller associated with at least one node of the resilient packet ring network, wherein the determination of the fair rate comprises determining a difference between a target queue length and the current transit queue length; and
stabilize one or more forwarding rates associated with the at least one node of the resilient packet ring network under unbalanced traffic scenarios, based at least in part on the allocated bandwidth,
wherein the fair rate F(n) is expressed as:
F ( n )= F ( n− 1)− k p ( e ( n )− e ( n− 1))
where F(n−1) is a prior fair rate, where K p is a proportional gain, where e(n) is the difference between a target queue length and a current transit queue length, and where e(n−1) is a prior difference between the target queue length and a current transit queue length.
6. The article of claim 5 , wherein the determination of a fair rate is based at least in part on rate of change of the difference between the target queue length and the current transit queue length.
7. The article of claim 5 , wherein the determination of a fair rate is based at least in part on a round trip delay between a bottleneck link of the resilient packet ring network and the at least one node of the resilient packet ring network.
8. The article of claim 5 , wherein the determination of a fair rate is based at least in part on a proportional gain k p expressed as:
0
<
k
p
<
π
2
W
τ
where W is a sum of weights associated with nodes of the resilient packet ring network, and where τ is based at least in part on a round trip delay between a bottleneck link of the resilient packet ring network and the at least one node of the resilient packet ring network.
9. A resilient packet ring network, comprising:
a plurality of nodes;
an inner ring of links associated between the plurality of nodes;
an outer ring of links associated between the plurality of nodes; and
a P-type controller associated with at least one of the plurality of nodes, wherein the P-type controller is configured to:
measure a current transit queue length;
determine a fair rate to facilitate an allocated bandwidth in the resilient packet ring network, wherein the determination of the fair rate comprises determining a difference between a target queue length and the current transit queue length, and
stabilize one or more forwarding rates associated with the at least one of the plurality of nodes under unbalanced traffic scenarios, based at least in part on the allocated bandwidth,
wherein the fair rate F(n) is expressed as:
F ( n )= F ( n− 1)− k p ( e ( n )− e ( n− 1))
where F(n−1) is a prior fair rate, where K p is a proportional gain, where e(n) is a difference between a target queue length and a current transit queue length, and where e(n−1) is the prior difference between the target queue length and a current transit queue length.
10. The resilient packet ring network of claim 9 , wherein the determination of a fair rate is based at least in part on a proportional gain k p expressed as:
0
<
k
p
<
π
2
W
τ
where W is a sum of weights associated with nodes of the resilient packet ring network, and where τ is based at least in part on a round trip delay between a bottleneck link of the resilient packet ring network and the at least one node of the resilient packet ring network.
11. An apparatus for use with a resilient packet network, comprising:
a P-type controller associated with at least one of a plurality of nodes in the resilient packet ring network, wherein the P-type controller is configured to:
measure a current transit queue length;
determine a fair rate to facilitate an allocated bandwidth in the resilient packet ring network, wherein the determination of the fair rate comprises determining a difference between a target queue length and the current transit queue length; and
stabilize one or more forwarding rates associated with the at least one of the plurality of nodes of the resilient packet ring network under unbalanced traffic scenarios, based at least in part on the allocated bandwidth,
wherein the fair rate F(n) is expressed as:
F ( n )= F ( n− 1)− k p ( e ( n )− e ( n− 1))
where F(n−1) is a prior fair rate, where K p is a proportional gain, where e(n) is a difference between a target queue length and a current transit queue length, and where e(n−1) is the prior difference between the target queue length and a current transit queue length.
12. The apparatus of claim 11 , wherein the P-type controller is further configured to determine the fair rate based at least in part on a proportional gain k p expressed as:
0
<
k
p
<
π
2
W
τ
where W is a sum of weights associated with nodes of the resilient packet ring network, and where τ is based at least in part on a round trip delay between a bottleneck link of the resilient packet ring network and the at least one node of the resilient packet ring network.