Guaranteed quality of service in an asynchronous metro packet transport ring
View Patent ↗An asynchronous metropolitan packet transport ring having guaranteed QoS. Asynchronous packetized data flow in one direction through a fiber optic loop. A number of Metropolitan Packet Switches (MPS) are coupled to the fiber optic loop. An MPS allows packetized data from an upstream MPS to flow to a downstream MPS over a segment of the fiber optic loop. The MPS also puts packetized data onto and pulls packetized data off of the fiber optic loop. Thereby, flows can access the fiber optic loop via the MPS's. The MPS's also regulate the data rates on a per-flow basis according to setup information supplied by a Ring Management System (RMS). If one segment of the fiber loop becomes overly congested, the MPS guarantees quality of service for those flows by deallocating available bandwidth from flows upstream to the point of congestion. Utilization of packet transport ring capacity is optimized by allocating any bandwidth that becomes available to active flows according to a pre-specified weighting scheme.
1. A metropolitan area packet rings comprising:
a fiber optic loop carrying asynchronous data packets, wherein the asynchronous data packets flow in a single direction through the fiber optic loop;
a plurality of metropolitan packet switches coupled to the fiber optic loop, wherein a metropolitan packet switch is comprised of an I/O port coupled to the fiber optic loop which inserts packets of data onto the fiber optic loop and which pulls packets of data off the fiber optic loop;
a processor coupled to the I/O Port which separately increases and decreases data rates at which existing individual flows of data packets are transmitted over the fiber optic loop, the data rates increased or decreased on a per-flow basis, wherein said increases and decreases are performed while maintaining quality of service on a per-flow basis.
2. The metropolitan area packet ring of claim 1 :
wherein the processor decreases a data rate of a flow upstream to a point of congestion in order to maintain quality of service.
3. The metropolitan area packet ring of claim 1 :
wherein bandwidth that becomes available is allocated amongst a plurality of flows.
4. The metropolitan area packet ring of claim 3 :
wherein the metropolitan packet switch allocates available bandwidth according to a pre-determined weighting scheme.
5. The metropolitan area packet ring of claim 1 further comprising:
a ring management system coupled to one of the metropolitan packet switches which sets up the metropolitan packed switches in order to maintain pre-determined quality of service on a per-flow basis.
6. The metropolitan area packet ring of claim 1 :
wherein the quality of service includes a variable bit rate with a minimum bandwidth.
7. The metropolitan area packet ring of claim 1 :
wherein the quality of service includes a constant bit rate with a minimum delay.
8. The metropolitan area packet ring of claim 1 :
wherein the metropolitan packet switch performs rate shaping.
9. The metropolitan area packet ring of claim 1 :
wherein the data packets transmitted through the fiber loop comprise 10 gigabit Ethernet.
10. In a metropolitan area packet ring having a plurality of switching devices through which a plurality of devices are coupled to the metropolitan area packet ring, a method for managing packetized traffic flowing asynchronously in a single direction through the metropolitan area packet ring to maintain a particular quality of service for a subscriber, comprising the steps of:
assigning the particular quality of service to the subscriber;
a plurality of metropolitan packet switches of the ring increasing or decreasing existing rates of individual flows of said asynchronous data packets being transmitted over the metropolitan area packet rings on a per-flow basis so as to provide the subscriber with a minimum bandwidth uni-directional QoS flow, regardless of the congestion on the metropolitan area packet ring.
11. The method of claim 10 further including the steps of:
determining packetized data congestion corresponding to particular segments of the metropolitan area packet ring;
adjusting a data rate upstream to a point of congestion in order to maintain that the minimum bandwidth assigned to the subscriber is being met.
12. The method of claim 10 further comprising the step of:
allocating bandwidth that becomes available to subscribers according to a pre-determined weighting scheme.
13. The method of claim 10 :
wherein the packetized data flowing through the fiber optic loop is comprised of Ethernet packets.
14. The method of claim 13 :
wherein the fiber optic loop is comprised of 10 Gbit Ethernet.
15. The method of claim 10 :
wherein the quality of service corresponds to either a variable bit rate with a minimum bandwidth or a constant bit rate with a minimum delay.
16. A metropolitan packet switch for routing packetized data in a packet ring, comprising:
a first port configured to insert data packets onto the packet ring;
a second port, downstream from the first port, configured to take data packets off from the packet ring;
a processor coupled to the first port which regulates data packets flowing asynchronously through the packet ring on a per-flow basis, by increasing or decreasing the data rate of existing individual flows, wherein
bandwidth which becomes available is re-allocated in accordance with a predetermined weighting scheme;
the asynchronous data packets flow in a single direction through the packet ring; and the data rate of a unidirectional QoS flow is maintained on a per-flow basis.
17. The device of claim 16 :
wherein the processor adjusts the data rates such that quality of service is maintained.
18. The device of claim 16 :
wherein the processor controls a rate by which data packets belonging to upstream flows are allowed to be inserted onto the packet ring.
19. The device of claim 16 further comprising:
a circuit which allocates available bandwidth on a per-flow basis.
20. The device of claim 16 :
wherein the data rates of upstream flows are increased according to a pre-determined weighting scheme.
21. The device of claim 16 :
wherein the packet ring is comprised of a fiber loop.
22. In a metropolitan area packet ring having a plurality of switching devices coupled to the packet ring, a method to manage packetized traffic flowing asynchronously in one direction through the packet ring, comprising the steps of:
assigning initial bandwidths corresponding to a plurality of subscribers;
determining packetized data congestion in the metropolitan area packet ring, wherein if bandwidth becomes available, newly available bandwidth is allocated to be used by the subscribers; and
a plurality of metropolitan packet switches providing the plurality of subscribers with respective minimum bandwidth unidirectional QoS flows on a per-flow basis, by increasing and decreasing data rates at which existing individual flows of data packets are transmitted over the packet ring the data rates increased or decreased on a per-flow basis, said increases and decreases performed while maintaining quality of service on a per-flow basis.
23. The method of claim 22 further comprising the step of:
allocating the available bandwidth to flows according to a pre-determined weighting scheme.
24. The method of claim 22 further comprising the step of:
controlling rates by which packetized data is allowed to be inserted onto the packet ring in order to provide quality of service for a set of the subscribers.
25. The method of claim 24 further comprising the step of:
reducing a data rate of an upstream flow to maintain the quality of service for a subscriber.
26. The method of claim 22 :
wherein the packet ring comprises a fiber optic loop and the packetized data is comprised of Ethernet packets.