IP routing pool distribution among forwarding elements in SDN service core deployment

• US 10,069,904 B2
• Filed: 10/26/2015
• Issued: 09/04/2018
• Est. Priority Date: 10/26/2015
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Singh, Akshya Kumar, Johnson, David Alan
• Primary Examiner(s): SHINGLES, KRISTIE D
• Application Number:
  US14/923,146
• Publication Number:
  US 20170118275A1
• Time in Patent Office: 1,044 Days
• Field of Search: 709226
• CPC Class Codes: H04L 61/5007 Internet protocol [IP] addresses
• CPC Class Codes: H04L 61/5014 using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]
• CPC Class Codes: H04L 61/5061 Pools of addresses
• CPC Class Codes: H04L 61/5092 by self-assignment, e.g. picking addresses at random and testing if they are already in use
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers

Abstract

An example method for load-balanced IP pool distribution among a plurality of forwarding elements is provided. The method may include assigning a plurality of IP pool chunks to the plurality of forwarding elements, each IP pool chunk comprising a plurality of IP addresses, and receiving, from each of the forwarding elements, information indicative of a load on each forwarding element. The method may further include performing load balancing using the information indicative of the load on each forwarding element to determine whether re-assignment of the plurality of IP pool chunks is needed, and re-assigning at least one IP pool chunk of the plurality of IP pool chunks from a first forwarding element to a second forwarding element based on the load balancing.

Claims

1. A system for providing load-balanced Internet Protocol (IP) pool distribution, the system comprising:

at least one memory element configured to store computer executable instructions, and at least one processor coupled to the at least one memory element and configured, when executing the instructions, to;

assign a plurality of IP pool chunks to a plurality of forwarding elements, wherein each IP pool chunk comprises a plurality of IP addresses;

receive, from each of the plurality of forwarding elements, load information for each forwarding element;

perform load balancing using the load information for each forwarding element to determine whether re-assignment of the plurality of IP pool chunks is needed;

when re-assignment of the plurality of IP pool chunks is needed, un-assign at least one IP address of at least one IP pool chunk assigned to a first forwarding element;

wait for a predetermined period of time; and

re-assign, after the predetermined period of time has elapsed, the at least one IP pool chunk from the first forwarding element to a second forwarding element.

2. The system according to claim 1, wherein the at least one processor is further configured to:

stop assigning of IP addresses of the at least one IP pool chunk to new subscriber sessions, and

re-assign the at least one IP pool chunk from the first forwarding element to the second forwarding element when all existing subscriber sessions utilizing IP addresses of the at least one IP pool chunk have finished.

3. The system according to claim 1, wherein the at least one processor is further configured to:

stop assigning of IP addresses of the at least one IP pool chunk to new subscriber sessions,

determine whether a number of existing subscriber sessions that utilize any of the plurality of IP addresses of the at least one IP pool chunk satisfy one or more conditions, and

re-assign the at least one IP pool chunk from the first forwarding element to the second forwarding element upon positive determination.

4. The system according to claim 1, wherein the at least one processor is further configured to trigger advertisement of IP addresses of the at least one IP pool chunk after the at least one IP pool chunk has been re-assigned from the first forwarding element to the second forwarding element.

5. The system according to claim 4, wherein advertising IP addresses of the at least one IP pool chunk comprises sending one or more Border Gateway Protocol (BGP) update messages comprising network layer reachability information (NLRI) for the IP addresses of the at least one IP pool chunk and a NEXT HOP path attribute encoding an identification of the second forwarding element.

6. The system according to claim 1, wherein the load information for each forwarding element comprises information indicative of packet and/or byte count of data traffic processed by the forwarding element, and/or wherein the load information for each forwarding element is received using an Open Flow protocol.

7. The system according to claim 1, wherein the system is a packet data network gateway (PGW).

8. The system according to claim 1, further comprising the plurality of forwarding elements.

9. A method for providing load-balanced Internet Protocol (IP) pool distribution, comprising:

assigning a plurality of IP pool chunks to a plurality of forwarding elements, wherein each IP pool chunk comprises a plurality of IP addresses;

receiving, from each of the plurality of forwarding elements, load information for each forwarding element;

performing load balancing using the load information for each forwarding element to determine whether re-assignment of the plurality of IP pool chunks is needed; and

when re-assignment of the plurality of IP pool chunks is needed, un-assigning at least one IP address of at least one IP pool chunk assigned to a first forwarding element;

waiting for a predetermined period of time; and

re-assigning, after the predetermined period of time has elapsed, the at least one IP pool chunk from the first forwarding element to a second forwarding element.

10. The method according to claim 9, further comprising:

stopping assigning of IP addresses of the at least one IP pool chunk to new subscriber sessions, and

re-assigning the at least one IP pool chunk from the first forwarding element to the second forwarding element when all existing subscriber sessions utilizing IP addresses of the at least one IP pool chunk have finished.

11. The method according to claim 9, further comprising:

stopping assigning of IP addresses of the at least one IP pool chunk to new subscriber sessions,

determining whether a number of existing subscriber sessions that utilize any of the plurality of IP addresses of the at least one IP pool chunk is below a threshold, and

re-assigning the at least one IP pool chunk from the first forwarding element to the second forwarding element upon positive determination.

12. The method according to claim 9, further comprising assigning IP addresses of the at least one IP pool chunk to new subscriber sessions after the at least one IP pool chunk has been re-assigned from the first forwarding element to the second forwarding element.

13. The method according to claim 9, further comprising triggering advertisement of IP addresses of the at least one IP pool chunk after the at least one IP pool chunk has been reassigned from the first forwarding element to the second forwarding element.

14. The method according to claim 9, wherein each IP address of the plurality of IP addresses is an IP address for carrying user data between a User Equipment (UE) and an external packet data network (PDN) over a cellular wireless telecommunications network.

15. One or more non-transitory tangible media encoding logic that include instructions for execution that, when executed by a processor, are operable to perform operations for providing load-balanced Internet Protocol (IP) pool distribution comprising:

assigning a plurality of IP pool chunks to a plurality of forwarding elements, wherein each IP pool chunk comprises a plurality of IP addresses;

receiving, from each of the plurality of forwarding elements, load information for each forwarding element;

performing load balancing using the load information for each forwarding element to determine whether re-assignment of the plurality of IP pool chunks is needed;

when re-assignment of the plurality of IP pool chunks is needed, un-assigning at least one IP address of at least one IP pool chunk assigned to a first forwarding element;

waiting for a predetermined period of time; and

re-assigning, after the predetermined period of time has elapsed, the at least one IP pool chunk from the first forwarding element to a second forwarding element.

16. The media according to claim 15, wherein the operations further comprise:

stopping assigning of IP addresses of the at least one IP pool chunk to new subscriber sessions,

determining whether a number of existing subscriber sessions that utilize any of the plurality of IP addresses of the at least one IP pool chunk is below a threshold, and

re-assigning the at least one IP pool chunk from the first forwarding element to the second forwarding element upon positive determination.

17. The media according to claim 15, the operations further comprising providing an instruction for advertising IP addresses of the at least one IP pool chunk after the at least one IP pool chunk has been re-assigned from the first forwarding element to the second forwarding element.

18. The media according to claim 17, wherein advertising IP addresses of the at least one IP pool chunk comprises sending one or more Border Gateway Protocol (BGP) update messages comprising network layer reachability information (NLRI) for the IP addresses of the at least one IP pool chunk and a NEXT HOP path attribute encoding an identification of the second forwarding element.

19. The media according to claim 15, wherein the load information for each forwarding element comprises information indicative of packet and/or byte count of data traffic processed by the forwarding element.

20. The media according to claim 15, wherein each IP address of the plurality of IP addresses is an IP address for carrying user data between a User Equipment (UE) and an external packet data network (PDN) over a cellular wireless telecommunications network.