Policy Enforcement Within an IP Network

• US 20100284327A1
• Filed: 01/20/2006
• Published: 11/11/2010
• Est. Priority Date: 01/20/2006
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Miklos, Gyorgy
• Granted Patent: US 8,670,333 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• 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: H04W 28/02 Traffic management, e.g. flow control or congestion control
• CPC Class Codes: H04W 28/16 Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
• CPC Class Codes: H04W 8/082 for traffic bypassing of mobility servers, e.g. location registers, home PLMNs or home agents
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 80/10 adapted for application session management, e.g. SIP [Session Initiation Protocol] connection management H04W76/00; arrangements for session management H04L67/14

Abstract

A method and network node for generating and applying policy rules in an IP network. A Policy Enforcement Function (PEF) is implemented in a node such as a Gateway GPRS Service Node (GGSN) routing packet flows to and from network users. An Application Function (AF) determines source and destination addressing information for a packet flow and sends the information to a Policy and Charging Decision Function in a Policy and Charging Control Function (PCRF) having access to service and mobility policies for network users. The PCRF generates policy rules based on the addressing information and the appropriate service and mobility policies. The PCRF sends the policies rules to the PEF for application to the traffic flow.

Claims

1. A method of generating and applying a set of policy rules for enforcement by a policy enforcement function at a node of a communication network, said node routing packet flows to and from users of the network, the method comprising:

at a service level control function, determining source and destination addressing information for a packet flow to be transported through said node;

sending said determined addressing information to a policy rules generating function, the policy rules generating function maintaining or having access to service and mobility policies for users of the communication network;

at the policy rules generating function, generating said set of policy rules on the basis of the source and destination addressing information and the appropriate service and mobility policies, the rules specifying a route optimization policy; and

sending the generated set of policy rules to the policy enforcement function; and

applying the set of policy rules to traffic flows to determine whether or not route optimization is allowed.

2. The method according to claim 1, wherein said service policy is a policy which takes no account of mobility.

3. The method according to claim 1, wherein said mobility policy defines access rights to Mobile IP for a plurality of users.

4. The method according to claim 1, wherein said mobility policy specifies for a user, Correspondent Nodes with which the user is permitted to employ route optimization.

5. The method according to claim 1, wherein said mobility policy specifies Home Agents via which a user is permitted to route Mobile IP traffic.

6. The method according to claim 1, wherein said mobility policy specifies packet types which are permitted to be used with Mobile IP.

7. The method according to claim 1, wherein said service level control function is located within a node of an IP Multimedia Subsystem, and the policy enforcement function is located with a GGSN of a cellular telephone network.

8. The method according to claim 1, wherein said source and destination addressing information provided by the service level control function comprises at least the source and destination addresses of the packet flow.

9. The method according to claim 8, wherein said addressing information also comprises the source and destination port numbers.

10. The method according to claim 1, further comprising sending from the service level control function to the policy rules generating function, an identification of a transport protocol utilized for the traffic flow, the policy rules generating function using knowledge of the transport protocol to generate the policy rules.

11. The method according to claim 1, wherein the policy rules generating function comprises a first part for applying said service policies to the received addressing information to generate a set of service rules, and a second part for applying the mobility policy to the service rules to generate said set of policy rules.

12. The method according to claim 11, wherein said second part extends the service rules to take into account Mobile IP addressing formats.

13. The method according to claim 12, wherein said service rules include source and destination address information for the IP flow, while each policy rule includes the home and care-of-address of the user for whom a policy is being applied, Correspondent Node home and care-of-addresses or address ranges, and an action for packets matching these address conditions.

14. The method according to claim 1, wherein a policy rule specifies allowed or disallowed Home Agent addresses and packet types.

15. The method according to claim 1, wherein a policy rule comprises includes the following fields:

Mobile Node home address;

Mobile Node care-of-address;

Home Agent address (or address range);

Correspondent Node home address;

Correspondent Node care-of-address;

Packet category identifying whether or not Mobile IP applies to a packet and if so, in what manner Mobile IP applies;

Transport protocol;

Mobile Node side port number; and

Correspondent Node side port number.

16. The method according to claim 1, wherein a policy rule includes a priority value which identifies to the policy enforcement function the priorities with which the policy rules are to be applied.

17. A node for use within a communication network, the node comprising:

means for receiving from a service level control function, addressing information relating to a packet flow through the network;

policy rules generating means having access to service and mobility policies for users of the communication network, and being arranged to generate a set of policy rules based on source and destination addressing information and the appropriate service and mobility policies, the rules specifying a route optimization policy; and

means for sending the generated set of policy rules to a policy enforcement function within the communication network.