Method and apparatus for defining and implementing high-level quality of service policies in computer networks

• US 7,185,073 B1
• Filed: 12/01/2000
• Issued: 02/27/2007
• Est. Priority Date: 10/26/1998
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: McCloghrie, Keith, Gai, Silvano
• Primary Examiner(s): Winder; Patrice
• Application Number:
  US09/728,138
• Time in Patent Office: 2,279 Days
• Field of Search: 709/223, 709/224, 709/221, 709/222, 709/225, 709/229, 709/220, 713/201
• US Class Current: 709/221
• CPC Class Codes: H04L 41/0893 Assignment of logical groups to network elements
• CPC Class Codes: H04L 41/0894 Policy-based network configuration management
• CPC Class Codes: H04L 41/5003 Managing SLA; Interaction between SLA and QoS
• CPC Class Codes: H04L 41/5054 Automatic deployment of services triggered by the service manager, e.g. service implementation by automatic configuration of network components
• CPC Class Codes: H04L 41/5096 wherein the managed service relates to distributed or central networked applications

Abstract

A computer network having multiple, dissimilar network devices includes a system for implementing high-level, network policies. The high-level policies, which are generally device-independent, are translated by one or more policy servers into a set of rules that can be put into effect by specific network devices. Preferably, a network administrator selects an overall traffic template for a given domain and may assign various applications and/or users to the corresponding traffic types of the template. Location-specific policies may also be established by the network administrator. The policy server translates the high-level policies inherent in the selected traffic template and location-specific policies into a set of rules, which may include one or more access control lists, and may combine several related rules into a single transaction. Intermediate network devices, which may have one or more roles assigned to their interfaces, are configured to request traffic management information from the policy server which replies with a particular set of transactions and rules. The rules, which may correspond to the particular roles assigned to the interfaces, are then utilized by the intermediate devices to configure their particular services and traffic management mechanisms. Other rules are utilized by the intermediate devices to classify packets with a particular priority and/or service value and to treat classified packets in a particular manner so as to realize the selected high-level policies within the domain.

Claims

1. In a policy server for connection to a computer network having a plurality of intermediate network devices each supporting a respective set of network services, whereby at least some of the network services differ among the intermediate network devices, a method for implementing high-level, device-independent traffic management policies within the computer network, the method comprising the steps of:

receiving one or more high-level policies;

translating the one or more high-level policies into a plurality of executable rules;

receiving a request for traffic management policies from an intermediate network device, wherein the request specifies a set of network services that are supported by the particular network device that issued the request;

selecting, in response to the request, one or more rules that are compatible with the network services specified by the intermediate network device; and

forwarding the selected one or more rules to the intermediate network device, wherein different rules are selected and forwarded to at least some of the intermediate network devices as a result of the differing network services that they support.

2. The method of claim 1 wherein the step of translating comprises the step of performing an algorithmic transformation on traffic management information from one or more traffic templates to obtain at least one of classification, behavioral and configuration rules.

3. The method of claim 1 wherein at least one of the one or more high level policies is associated with one or more predefined roles.

4. The method of claim 3 wherein the request for traffic management policies includes one or more roles that have been assigned to the requesting intermediate network device.

5. The method of claim 4 wherein the intermediate network devices include a plurality of interfaces for forwarding network messages and, the roles refer to predefined operating characteristics of the interfaces.

6. The method of claim 4 wherein at least one of the one or more roles indicates that the requesting intermediate network device is coupled to a backbone network.

7. The method of claim 4 wherein at least one of the one or more roles indicates that the requesting intermediate network device is coupled to a subscribing network to which a traffic specifier is to be applied.

8. The method of claim 7 wherein the one or more policies are communicated to the intermediate network device using a Common Open Policy Service (COPS) protocol.

9. In an intermediate network device, a method for implementing high-level traffic management policies, the method comprising the steps of:

identifying one or more network services that the network device supports;

issuing a request for traffic management policies, the request specifying the one or more identified network services that are supported;

receiving one or more rules for managing network traffic at the intermediate network device; and

utilizing the one or more rules to configure the one or more network services so as to realize the high-level traffic management policies.

10. The method of claim 9 wherein the step of utilizing comprises the step of assigning a given treatment to network traffic based on one or more classification rules.

11. The method of claim 10 wherein at least one classification rule specifies a DS codepoint to be assigned to a given traffic type.

12. The method of claim 10 wherein the step of utilizing comprises the step of selecting a DS codepoint for use in loading at least one of a user priority field and a type of service field of a given network message based on the traffic type of the given network message.

13. The method of claim 12 wherein the step of utilizing further comprises the step of loading the least one of user priority field and type of service field of the given network message with the selected DS codepoint.

14. The method of claim 10 wherein at least one classification rule specifies a quality of service (QoS) label to be applied to network traffic within the intermediate network device matching one or more criteria.

15. The method of claim 14 wherein the step of utilizing comprises the step of applying the specified QoS label to network traffic matching the one or more criteria.

16. The method of claim 9 wherein at least one rule identifies a preferred congestion algorithm to be implemented at the network device.

17. The method of claim 16 wherein the preferred congestion algorithm is one of weighted fair queuing, weighted round robin and priority queuing.

18. The method in claim 9 wherein the intermediate network device has plurality of queues associated with the interfaces for storing network messages to be forwarded from the interfaces,

each queue has one or more thresholds;

and

the one or more network services include the number of queues associated with a given interface and the number of thresholds associated with a given queue.

19. The method of claim 9 further comprising the steps of:

having one or more roles assigned to the network device; and

including, within the request for traffic management policies, the one or more assigned roles.

20. The method of claim 19 wherein one or more of the received rules are associated with the roles assigned to the network device.

21. The method of claim 20 further comprising the steps of:

matching the role of a received rule to a network service supported by the network device; and

configuring the matching network service to realize the assigned role.

22. The method of claim 19 wherein

the intermediate network device includes a plurality of interfaces for forwarding network messages;

and

the roles refer to predefined operating characteristics of the interfaces.

23. The method of claim 9 wherein the supported network services include one or more of a policer entity, a shaper entity, a marker entity, a dropper entity and a queue selector entity.

24. The method of claim 9 wherein the request is issued to and the rules are received from a policy server with which the network device is in communicating relationship.

25. A policy server for use in implementing high-level, device-independent traffic management policies within a computer network having a plurality of intermediate network devices and one or more information resources, the intermediate network devices each supporting a respective set of network services, whereby at least some of the network services differ among the intermediate network devices, the policy server comprising:

a policy translator that is configured to receive the high-level traffic management policies including one or more corresponding data structures, and to access the one or more information resources for inserting information in the data structures;

a policy rule generating engine coupled to the policy translator and configured to translate the data structures into one or more executable traffic management rules;

a device-specific filter entity coupled to the policy rule generating engine and configured to select a subset of the one or more traffic management rules in response to a request from a respective intermediate network device having particular traffic management resources and services; and

a communication engine coupled to the device-specific filter entity for exchanging requests from intermediate network devices and selected subsets of the one or more traffic management rules, wherein the device-specific filter entity selects different rule subsets for transmission to the intermediate network devices as a result of the differing network services that they support.

26. The policy server of claim 25, wherein the policy rule generating engine is further configured to algorithmically transform traffic management information from one or more traffic templates to obtain at least one of classification, behavioral and configuration rules.

27. The policy server of claim 25, wherein at least one of the high level policies is associated with one or more predefined roles.

28. The policy server of claim 27, wherein the request from the intermediate network device includes one or more roles that have been assigned to the requesting intermediate network device.

29. The policy server of claim 28, wherein at least one of the one or more roles indicates that the requesting intermediate network device is coupled to a backbone network.

30. The policy server of claim 28, wherein at least one of the one or more roles indicates that the requesting intermediate network device is coupled to a subscribing network to which a traffic specifier is to be applied.

31. The policy server of claim 30, wherein the one or more policies are communicated to the intermediate network device using a Common Open Policy Service (COPS) protocol.

32. A network device for use in forwarding network messages in a computer network, the network device comprising:

a plurality of interfaces from which the network messages may be received and sent;

a plurality of network services coupled to the interfaces for use in examining and processing the network messages; and

a traffic management controller operatively coupled to the network services, wherein

the traffic management controller issues a request for traffic management policies, receives one or more policies in response to the request, and configures the network services so as to realize the received policies wherein the traffic management controller issues a request for traffic management policies, receives one or more policies in response to the request, and configures the network services so as to realize the received policies wherein the request specifies one or more of the network device'"'"'s network services so that the received policies will be compatible therewith.

33. A method for setting traffic management policies in a computer network, comprising:

receiving one or more high-level policies, wherein the one or more high-level policies include one or more corresponding data structures;

translating the one or more high-level policies into a plurality of executable rules by translating the one or more data structures into executable rules;

receiving a request for traffic management policies from an intermediate network device, wherein the request specifies a set of network services that are supported by the particular network device that issued the request;

in response to the request, selecting, by filtering, one or more rules that are compatible with the network services specified by the intermediate network device; and

forwarding the selected one or more rules to the intermediate network device, wherein a process on the intermediate device selects different rules and forwards the rules to at least some of the plurality of intermediate network devices as a result of the differing network services that they support.