Providing admission control and network quality of service with a distributed bandwidth broker
First Claim
1. A method of making admission control decisions in a packet switched network, the method comprising:
- calculating an average premium service bandwidth used during a predetermined window of time on an output link of a network device; and
determining whether to accept or reject a request for a premium service flow by evaluating the following expression;
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Accused Products
Abstract
A method and apparatus are provided for making admission decisions in a packet switched network, such as a Differentiated Services (DiffServ) Packet Network. According to one aspect of the present invention, admission control decisions are based upon local information. An average premium service bandwidth utilized on an output link of a network device during a predetermined window of time is calculated. A determination regarding whether to accept or reject a request for a premium service flow involving the output link is made based upon the request, a total premium service bandwidth available on the output link, the average premium service bandwidth, and bandwidth request information associated with one or more flows that have been admitted within a predetermined holding time interval. According to another aspect of the present invention, multicast flows are supported. A measure of utilized premium service bandwidth is calculated for each of the output links of a multicast-capable network device. A request for premium service bandwidth for a multicast session is forwarded onto those of the output links specified by a multicast routing protocol which have sufficient premium service bandwidth available to accommodate the request based upon the total premium service bandwidth available on the output link, the measure of utilized premium service bandwidth on the output link, and the request. For each of the output links associated with the multicast session, a link state is maintained. The link state indicates the current state of a state machine that determines the behavior of the multicast-capable network device for the corresponding output link of the multicast session. Multicast packets that are subsequently received are forwarded according to the link states associated with the output links.
175 Citations
16 Claims
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1. A method of making admission control decisions in a packet switched network, the method comprising:
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calculating an average premium service bandwidth used during a predetermined window of time on an output link of a network device; and
determining whether to accept or reject a request for a premium service flow by evaluating the following expression;
- View Dependent Claims (2, 3)
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4. A method of making admission control decisions in a packet switched network, the method comprising:
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calculating an average premium service bandwidth used during a predetermined window of time on an output link of a network device; and
determining whether to accept or reject a request for a premium service flow involving the output link based upon the request, a total premium service bandwidth available on the output link, the average premium service bandwidth, and bandwidth request information associated with one or more flows that have been admitted within a predetermined holding time interval, the determining of whether to accept or reject the request comprises accepting the request when the following expression is true and rejecting the request when it is false;
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5. A method of making admission control decisions in a Differentiated Services Packet Network, the method comprising:
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determining a measure of utilized premium service bandwidth on an output link of a network device by periodically calculating an average premium service bandwidth used during a predetermined window of time, and adding to the average premium service bandwidth a bandwidth associated with a flow that has been admitted but that has not yet started to inject premium packets onto the output link; and
determining whether to accepting or reject a request for a premium service flow involving the output link based upon a total premium service bandwidth available on the output link, the measure of utilized premium service bandwidth on the output link and the request, the determining whether to accepting or reject the request comprises accepting the request when the following expression is true and rejecting the request when it is false;
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6. A method of making admission control decisions regarding premium unicast flows in a packet switched network without maintaining permanent per-flow state information for accepted unicast flows, the method comprising:
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temporarily storing bandwidth request information associated with admitted unicast flows that have been admitted within a predetermined holding time interval;
calculating an average premium service bandwidth used during a predetermined window of time on an output link of a network device;
determining whether to accept or reject a request for a premium service flow involving the output link based upon the request, a total premium service bandwidth available on the output link, the average premium service bandwidth, and the bandwidth request information based on an expression;
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7. A method of making admission control decisions in a Differentiated Services Packet Network, the method comprising:
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periodically determining a measure of utilized premium service bandwidth on an output link of a network device based upon an average premium service bandwidth used during a predetermined window of time and requested bandwidth associated with at least one flow that has been admitted but that has not yet started to inject premium packets onto the output link;
receiving a request for premium service bandwidth over the output link; and
determining whether to accepting or reject the request based upon a total premium service bandwidth available on the output link, the measure of utilized premium service bandwidth on the output link, and the request in accordance with an expression;
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8. A method of managing multicast flows in a Differentiated Services Packet Network, the method comprising the steps of:
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receiving a request for premium service bandwidth for a multicast flow;
identifying one or more output links of a multicast-capable network device that are part of the multicast flow;
forwarding the request onto those of the one or more output links that satisfy an admission criterion, the admission criterion comprises the following expression;
- View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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16. A network device comprising:
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a storage device having stored therein one or more routines for implementing admission control policy based on local information;
a processor coupled to the storage device for executing the one or more routines to make an admission decision regarding a request for establishment of a flow, where;
an average premium service bandwidth utilized during a predetermined window of time is determined for an output link through which the flow will pass;
bandwidth request information associated with one or more flows that have been admitted within a predetermined time interval is temporarily stored; and
an admission criterion is evaluated based upon a following expression;
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Specification