Service redundancy in wireless networks

• US 8,264,956 B2
• Filed: 03/01/2010
• Issued: 09/11/2012
• Est. Priority Date: 02/27/2009
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Ramankutty, Rajesh, Chowdhury, Kuntal
• Primary Examiner(s): ABELSON, RONALD B
• Application Number:
  US12/715,275
• Publication Number:
  US 20100220656A1
• Time in Patent Office: 925 Days
• Field of Search: 370/228, 370/328
• US Class Current: 370/228
• CPC Class Codes: H04L 45/025 Updating only a limited number of routers, e.g. fish-eye update
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04W 24/04 Arrangements for maintaining operational condition
• CPC Class Codes: H04W 88/14 Backbone network devices
• CPC Class Codes: H04W 88/16 Gateway arrangements

Abstract

This disclosure relates to an apparatus and method for providing service redundancy among devices in a communication network. The devices can be, for example, a mobility management entity (MME), a serving gateway (SGW), a PDN gateway (P-GW), a call session control function (CSCF), a SGSN, a GGSN, or any other device implemented on a chassis. The redundancy includes a geographic redundancy where the devices are remotely located from one another to prevent a service outage. The devices can provide redundancy to multiple other devices, such that one device serves as a backup to multiple other devices. The information used to provide service to a mobile node such as user equipment can be backed up on the redundancy device and the device can advertise the same routing information to the network so the network is unaware of any change.

Claims

1. A method of providing geographic redundancy from a MME implemented on a chassis to a plurality of remote mobility management entities (MME), the method comprising:

receiving, at the MME, a configuration message from a first remote MME, which is used by the MME to configure the MME to provide geographic redundancy to the first remote MME;

receiving, at the MME, a configuration message from a second remote MME, which is used by the MME to configure the MME to provide geographic redundancy to the second remote MME;

receiving, at the MME, from the first remote MME, backup information that corresponds to active sessions on the first remote MME;

receiving, at the MME, from the second remote MME, backup information that corresponds to active sessions on the second remote MME;

creating, at the MME, redundant sessions corresponding to the sessions on the first remote MME and the second remote MME using the backup information received from the first remote MME and the second remote MME;

activating the redundant sessions on the MME for at least one of the first remote MME and the second remote MME when the MME detects a trigger from at least one of the first remote MME and the second remote MME; and

exchanging control signaling at the MME with at least one eNodeB and at least one serving gateway (SGW), wherein the MME takes over providing evolved mobility management and evolved session management in place of the at least one of the first remote MME and the second remote MME using the activated redundant sessions.

2. The method of claim 1, wherein the trigger includes at least one of:

an indication that a remote MME has failed, and an indication from the first remote MME to the MME to initiate a switchover.

3. The method of claim 1, wherein the MME resides on a chassis that includes line cards for input/output connectivity and application cards that provide functionalities including system control and management as well as packet processing.

4. The method of claim 3, further comprising:

executing, by a recovery control task, a recovery action for failures that occur in the chassis; and

transporting user data over a redundancy link when a hardware failure occurs in the chassis.

5. The method of claim 3, further comprising receiving, at a SGW function implemented on the chassis, packet data addressed to the SGW function, wherein the SGW function and the MME are implemented on the chassis.

6. The method of claim 1, wherein the MME includes active and standby partitions and the MME provides standby partitions for at least the first remote MME and the second remote MME.

7. The method of claim 1, further comprising broadcasting from the MME common loopback interface routes into at least one of a border gateway protocol (BGP).

8. The method of claim 7, further comprising receiving control signaling addressed to the first remote MME at the MME after broadcasting the common loopback interface routes.

9. The method of claim 1, further comprising exchanging with the first remote MME and the second remote MME a periodic service redundancy message that is used to determine when a failure occurs and trigger a switchover.

10. The method of claim 1, wherein the background information includes eNodeB connection states, node level states, evolved mobility management states, and evolved session states.

11. A mobility management entity (MME) that communicates with at least one remote MME to provide redundancy in case of failure, the MME comprising:

a service redundancy protocol (SRP) manager of the MME that provides redundancy to a remote MME, and where the SRP manager is configured to read incoming and form outgoing SRP control messages exchanged with the remote MME, wherein the SRP messages received include backup information for sessions on the remote MME;

a SRP session manager of the MME configured to communicate with the SRP manager to receive the backup information obtained from the remote MME and create redundant sessions that correspond to active sessions on the remote MME, wherein the redundant sessions are updated to allow the MME to activate the redundant sessions to provide MME functionality in place of the remote MME; and

wherein the MME is configured to transmit control signaling to at least one eNodeB and at least one serving gateway (SGW) after a trigger is detected by the SRP manager and a switchover is initiated.

12. The MME of claim 11, wherein the trigger includes at least one of:

an indication of a failure of the remote MME, and an indication from the remote MME to the MME to initiate a switchover.

13. The MME of claim 11, wherein the MME includes active and standby partitions, wherein the standby partitions correspond to an active partition on the remote MME.

14. The MME of claim 11, further comprising:

at least one line card configured to provide input/output connectivity;

at least one application card configured to provide functionalities including system control and management and packet processing;

a bus for coupling the at least one line card and the at least one application card in a chassis; and

a recovery control task residing on the at least one application card, and providing a recovery action for failures that occur in the chassis; and

a redundancy link coupled to the at least one application card and configured to transport data when a hardware failure occurs in the chassis.

15. The MME of claim 11, wherein the background information includes eNodeB connection states, node level states, evolved mobility management states, and evolved session states.

16. A chassis that implements a mobility management entity (MME) function and communicates with at least one remote chassis that implements a second MME function, the chassis comprising:

a service redundancy protocol (SRP) manager implemented by the chassis to provide redundancy to a plurality of remote chassis each implementing a MME, and where the SRP manager is configured to read incoming SRP control messages received from the plurality of remote chassis that include backup information on one of the plurality of remote chassis implementing a MME function;

a SRP session manager implemented by the chassis and configured to communicate with the SRP manager to receive backup information obtained from at least one of the plurality of remote chassis and create redundant sessions that correspond to active sessions on the at least one of the plurality of remote chassis, wherein the redundant sessions are updated to allow the chassis to activate the redundant sessions to provide MME functionality in place of an MME function residing on one of the plurality of remote chassis; and

a physical interface on the chassis configured to transmit control signaling from the MME function to at least one eNodeB and at least one serving gateway (SGW) after a trigger is detected by the SRP manager and a switchover is initiated.

17. The chassis of claim 16, wherein the trigger includes at least one of:

an indication of a failure of the one of the plurality of remote chassis, and an initiation from the one of the plurality of remote chassis to the chassis to initiate a switchover.

18. The chassis of claim 16, further comprising:

at least one line card configured to provide input/output connectivity;

at least one application card configured to provide functionalities including system control and management as well as packet processing; and

a bus for coupling the at least one line card and the at least one application card in the chassis.

19. The chassis of claim 18, further comprising:

a recovery control task residing on the at least one application card, and providing a recovery action for failures that occur in the chassis; and

a redundancy link coupled to the at least one application card and configured to transport data when a hardware failure occurs in the chassis.

20. The chassis of claim 16, wherein the chassis includes active and standby partitions for the MME and the chassis provides standby partitions for the plurality of remote chassis MME functions.

21. The chassis of claim 16, wherein the chassis is configured to broadcast common loopback interface routes into at least one of a border gateway protocol (BGP) for the MME after the trigger is detected.

22. The chassis of claim 16, further comprising a SGW function implemented on the chassis that is configured to receive packet data from a PDN gateway (PGW) addressed to the SGW function and send the packet data to an eNodeB.

23. The chassis of claim 16, wherein the background information includes eNodeB connection states, node level states, evolved mobility management states, and evolved session states.