GPRS default bearer tracking

1. A method performed by a policy and charging rules node (PCRN) in a packet switching network for managing default bearers, the method comprising:

receiving, at the PCRN, a request message to establish a new bearer for an Internet protocol connectivity access network (IP-CAN) session;

determining whether said request message includes a request for a service data flow (SDF); and, if said request message does not include the request for the SDF:

determining whether said IP-CAN session has an existing bearer with no SDF associated with it; and, if said IP-CAN session has no existing bearer with no SDF associated with it:

establishing said new bearer with no SDF; and

identifying said new bearer, in a Subscription Profile Repository (SPR), as a default bearer for said IP-CAN session.

2. The method of claim 1 , further comprising:

identifying a previous default bearer as not being the default bearer.

3. The method of claim 1 , further comprising:

determining if an existing default bearer has no SDF associated with it.

4. The method of claim 1 , wherein if said IP-CAN session has the existing bearer with no flow associated with it:

rejecting the request to establish the new bearer.

5. The method of claim 1 , wherein said packet switching network comprises a general packet radio service (GPRS) network.

6. The method of claim 1 , further comprising:

setting a default flag associated with the new bearer in a corresponding subscription profile in the SPR.

7. The method of claim 1 , further comprising: disabling the default flag in subscription profiles in the SPR that correspond to all other bearers.

8. The method of claim 1 , further comprising: storing an identifier of the default bearer in the SPR.

9. A method performed by a policy and charging rules node (PCRN) in a packet switching network for managing default bearers, the method comprising:

receiving, at the PCRN, a request message to remove a first service data flow (SDF) from a first bearer associated with an Internet protocol connectivity access network (IP-CAN) session;

determining whether first bearer has SDFs other than said first SDF; and, if said first bearer has no SDFs other than said first SDF:

determining whether said first bearer is identified as a default bearer for said IP-CAN session; and, if said first bearer is not identified as a default bearer for said IP-CAN session:

determining whether the default bearer for said IP-CAN session has at least one SDF; and if said default bearer for said IP-CAN session has at least one SDF:

removing said first SDF from said first bearer; and

identifying said first bearer with no SDF, in a Subscription Profile Repository (SPR), as a new default bearer for said IP-CAN session.

10. The method as claimed in claim 9 , further comprising:

identifying a previous default bearer as not being the default bearer.

11. The method of claim 9 , wherein said packet switching network comprises a general packet radio service (GPRS) network.

12. The method of claim 9 , further comprising: setting a default flag associated with the new bearer in a corresponding subscription profile in the SPR.

13. The method of claim 9 , further comprising: disabling the default flag in subscription profiles in the SPR that correspond to all other bearers.

14. The method of claim 9 , further comprising: storing an identifier of the default bearer in the SPR.

15. A policy and charging rules node (PCRN) for handling an incoming request message, the PCRN comprising:

at least one interface configured to receive a credit control request (CCR) message from a policy and charging enforcement node (PCEN); wherein said PCRN is configured to perform the method of claim 1 .

16. A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform the method of claim 1 .