Preallocation of Client Network Address Translation Addresses for Client-Server Networks

• US 20060248231A1
• Filed: 07/03/2006
• Published: 11/02/2006
• Est. Priority Date: 12/21/2000
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: O'Rourke, Chris, Batz, Robert M., Klein, Steven C., Housel, Barron C.
• Granted Patent: US 7,660,909 B2
• Time in Patent Office: Days
• US Class Current: 709/245
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/2514 between local and global IP addresses
• CPC Class Codes: H04L 61/255 Maintenance or indexing of mapping tables
• CPC Class Codes: H04L 61/50 Address allocation
• CPC Class Codes: H04L 61/5061 Pools of addresses

Abstract

An improved client network address translation (“NAT”) system is provided. Methods are provided for initializing connection control blocks with the client NAT addresses when a storage pool of connection control blocks are allocated. This avoids the costly overhead as connections are created and destroyed. Unlike the prior art solutions, once the connection control blocks of the present invention are allocated, they remain in effect until the storage subpool is deleted. Secondly, in order to provide as large a pool of client NAT addresses as possible, methods are provided for using intervals to allocate and reclaim client NAT addresses as subpools are allocated and freed.

Claims

1. A method for allocating memory for a client network address translation (NAT) pool, comprising:

creating a client NAT address range;

allocating a memory pool to store the client NAT address range;

allocating a first subpool of the memory pool upon receiving a connection request;

establishing connection blocks within the subpool;

assigning client NAT addresses to the connection blocks of the first subpool for each connection being requested;

allocating a second subpool when a number of connection blocks in the first subpool not being assigned a client NAT address reaches a threshold value.

2. The method of claim 1, further comprising:

freeing a particular connection block from its client NAT address assignment upon termination of its corresponding connection.

3. The method of claim 2, wherein the assigned client NAT addresses are not re-assignable until all connection blocks within the first subpool are free.

4. The method of claim 1, further comprising:

deleting the first subpool upon determining that all connection blocks of the first subpool are free.

5. The method of claim 4, further comprising:

deallocating the first subpool to the memory pool for use by an operating system.

6. A computer readable medium including code for allocating memory for a client network address translation (NAT) pool, the code operable to:

create a client NAT address range;

allocate a memory pool to store the client NAT address range;

allocate a first subpool of the memory pool upon receiving a connection request;

establish connection blocks within the subpool;

assign client NAT addresses to the connection blocks of the first subpool for each connection being requested;

allocate a second subpool when a number of connection blocks in the first subpool not being assigned a client NAT address reaches a threshold value.

7. The computer readable medium of claim 6, wherein the code is further operable to:

free a particular connection block from its client NAT address assignment upon termination of its corresponding connection.

8. The computer readable medium of claim 7, wherein the assigned client NAT addresses are not re-assignable until all connection blocks within the first subpool are free.

9. The computer readable medium of claim 6, wherein the code is further operable to:

delete the first subpool upon determining that all connection blocks of the first subpool are free.

10. The computer readable medium of claim 9, wherein the code is further operable to:

deallocate the first subpool to the memory pool for use by an operating system.

11. A system for allocating memory for a client network address translation (NAT) pool, comprising:

means for creating a client NAT address range;

means for allocating a memory pool to store the client NAT address range;

means for allocating a first subpool of the memory pool upon receiving a connection request;

means for establishing connection blocks within the subpool;

means for assigning client NAT addresses to the connection blocks of the first subpool for each connection being requested;

means for allocating a second subpool when a number of connection blocks in the first subpool not being assigned a client NAT address reaches a threshold value.

12. The system of claim 11, further comprising:

means for freeing a particular connection block from its client NAT address assignment upon termination of its corresponding connection.

13. The system of claim 12, wherein the assigned client NAT addresses are not re-assignable until all connection blocks within the first subpool are free.

14. The system of claim 11, further comprising:

deleting the first subpool upon determining that all connection blocks of the first subpool are free.

15. The system of claim 14, further comprising:

deallocating the first subpool to the memory pool for use by an operating system.

16. A system for allocating memory for a client network address translation (NAT) pool, comprising:

a load balancer operable to create a client NAT address range;

a memory manager operable to allocate a memory pool to store the client NAT address range, the memory manager operable to allocate a first subpool of the memory pool upon receiving a connection request;

an address manager operable to initialize connection blocks within the first subpool;

wherein the load balancer is operable to assign client NAT addresses to the connection blocks of the first subpool for each connection being requested;

wherein the memory manager is operable to allocate a second subpool when a number of connection blocks in the first subpool not being assigned a client NAT address reaches a threshold value.

17. The system of claim 16, wherein the address manager is operable to free a particular connection block from its client NAT address assignment upon termination of its corresponding connection.

18. The system of claim 17, wherein the assigned client NAT addresses are not re-assignable until all connection blocks within the first subpool are free.

19. The system of claim 16, further comprising:

deleting the first subpool upon determining that all connection blocks of the first subpool are free.

20. The system of claim 19, wherein the memory manager is operable to deallocate the first subpool to the memory pool for use by an operating system.