Apparatus and methods for maintaining the registration state of an IP device in a network address port translation (NAPT) environment

• US 7,480,305 B1
• Filed: 02/19/2002
• Issued: 01/20/2009
• Est. Priority Date: 02/19/2002
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Somasundaram, Mahadev
• Primary Examiner(s): Pham; Chi H
• Assistant Examiner(s): Mills; Donald L
• Application Number:
  US10/078,851
• Time in Patent Office: 2,527 Days
• Field of Search: 370/352, 370/392, 370400-402, 370/466, 370/467, 370/469, 375/211
• US Class Current: 370/401
• CPC Class Codes: H04L 61/2517 using port numbers
• CPC Class Codes: H04L 61/2564 for a higher-layer protocol, e.g. for session initiation protocol [SIP]

Abstract

Disclosed are methods and apparatus for managing a registration state of an endpoint node in a network address port translation environment. A registration message is received from a first endpoint node located within a local network. The registration message is sent from the first endpoint node to a gatekeeper node, and the registration message includes a local source address of the first endpoint node, a local source port of the first endpoint node, and local call signaling information to be used by another endpoint node to initiate a data connection with the first endpoint node. The local source address of the first endpoint node is translated into a first global address. A first binding that associates the local source address with the global source address is created. The local call signaling information is translated into global call signaling information. A registration state of the first endpoint node is maintained, and the first binding is maintained based on the registration state (e.g., by using “registration doors”).

Claims

1. A method for managing a registration state of an endpoint node in a network address port translation environment, the method comprising:

at a network address translation device, receiving a registration message from a first endpoint node located within a local network, the registration message being sent from the first endpoint node to a gatekeeper node, wherein the registration message includes a local source address of the first endpoint node, a first local source port of the first endpoint node, and local call signaling information;

at the network address translation device, translating the local source address and/or the first local source port of the first endpoint node into a first global address and/or a first global port, respectively;

at the network address translation device, creating a first binding that associates the local source address with the global source address and/or associates the first local source port with the first global port;

at the network address translation device, translating the local call signaling information into global call signaling information;

at the network address translation device, creating a second binding between the local call signaling information and the global call signaling information such that the second binding associates different local and global information than the first binding, wherein creating the first and second bindings is based on the registration message that was received at the network translation device; and

if an unregistration message is received from the first endpoint node, dismantling the first binding and the second binding at the network address translation device.

2. A method as recited in claim 1, wherein the second binding associates a second local source port of the local call signaling information with a second global port and wherein the second local source port differs from the first local port and the second global port differs from the first global port and wherein the local source address and first local source port are translated into the first global address and the first global port, respectively, and wherein the first global address and port and the second global source port can be used by another endpoint node to communicate with the first endpoint node.

3. A method as recited in claim 2, wherein the local call signaling information is within the payload of the registration message and further includes the local source address.

4. A method as recited in claim 1, further comprising:

setting a timer based on a time period associated with the registration message;

restarting the timer when a refresh message is received from the first endpoint node; and

dismantling the first and second binding if the timer expires.

5. A method as recited in claim 4, wherein creating the second binding includes creating a registration door containing the global call signaling information and the time period after which the registration of the first endpoint node is to expire, the time period originating from within the local call signaling information, and dismantling the second binding is further accomplished by dismantling the registration door if the timer expires or if an unregistration message is received from the first endpoint node.

6. A method as recited in claim 5, wherein the first binding is an entry within a NAT Table and the registration door is an entry within a Registration Table.

7. A method as recited in claim 1, further comprising:

creating a registration door containing the global call signaling information and a time period after which the registration of the first endpoint node is to expire, the time period originating from within the local call signaling information; and

associating the registration door with the first binding.

8. A method as recited in claim 7, wherein associating the registration door with the first binding is accomplished by forming a link there between the registration door and the first binding.

9. A method as recited in claim 7, further comprising:

receiving a communication message from a second endpoint node destined for the first endpoint node, the communication message being a first message to establish a data connection between the second and first endpoint, the communication message having a second source address, a second destination address, a second source port, and a second destination port, wherein the second destination address equals the first global address and the second destination port equals a first global port obtained from the global call signaling information;

translating the communication message based on the registration door; and

wherein creation of the second binding is based on the registration door, the second binding being useful for translating subsequent communication messages sent between the first and second endpoints.

10. A method as recited in claim 9, further comprising dismantling the registration door and its associated first binding if a timer associated with the registration message expires or if an unregistration message is received from the first endpoint node.

35. A method as recited in claim 1, wherein the first and second bindings are dismantled so that their global information can be used by other endpoint nodes.

11. A network address translation (NAT) system operable to manage a registration state of an endpoint node in a network address port translation environment, the NAT system comprising:

one or more processors;

one or more memory, wherein at least one of the processors and memory are adapted to;

receive a registration message from a first endpoint node located within a local network, the registration message being sent from the first endpoint node to a gatekeeper node, wherein the registration message includes a local source address of the first endpoint node, a first local source port of the first endpoint node, and local call signaling information;

translate the local source address and/or the first local source port of the first endpoint node into a first global address and/or a first global port, respectively;

create a first binding that associates the local source address with the global source address and/or associates the first local source port with the first global port;

translate the local call signaling information into global call signaling information;

create a second binding between the local call signaling information and the global call signaling information such that the second binding associates different local and global information than the first binding, wherein creating the first and second bindings is based on the registration message that was received at the network translation device; and

if an unregistration message is received from the first endpoint node, dismantle the first binding and the second binding.

12. A NAT system as recited in claim 11, wherein the second binding associates a second local source port of the local call signaling information with a second global port and wherein the second local source port differs from the first local port and the second global port differs from the first global port and wherein the local source address and first local source port are translated into the first global address and the first global port, respectively, and wherein the first global address and port and the second global source port can be used by another endpoint node to communicate with the first endpoint node.

13. A NAT system as recited in claim 12, wherein the local call signaling information is within the payload of the registration message and further includes the local source address.

14. A NAT system as recited in claim 11, wherein at least one of the processors and memory are further adapted to:

set a timer based on a time period associated with the registration message;

restart the timer when a refresh message is received from the first endpoint node and

dismantle the first and second binding if the timer expires.

15. A NAT system as recited in claim 14, wherein creating the second binding includes creating a registration door containing the global call signaling information and the time period after which the registration of the first endpoint node is to expire, the time period originating from within the local call signaling information, and dismantling the second binding is further accomplished by dismantling the registration door if the timer expires or if an unregistration message is received from the first endpoint node.

16. A NAT system as recited in claim 15, wherein the first binding is an entry within a NAT Table and the registration door is an entry within a Registration Table.

17. A NAT system as recited in claim 11, wherein at least one of the processors and memory are further adapted to:

creating a registration door containing the global call signaling information and a time period after which the registration of the first endpoint node is to expire, the time period originating from within the local call signaling information; and

associating the registration door with the first binding.

18. A NAT system as recited in claim 17, wherein associating the registration door with the first binding is accomplished by forming a link there between the registration door and the first binding.

19. A NAT system as recited in claim 17, wherein at least one of the processors and memory are further adapted to:

receive a communication message from a second endpoint node destined for the first endpoint node, the communication message being a first message to establish a data connection between the second and first endpoint, the communication message having a second source address, a second destination address, a second source port, and a second destination port, wherein the second destination address equals the first global address and the second destination port equals a first global port obtained from the global call signaling information;

translate the communication message based on the registration door; and

wherein creation of the second binding is based on the registration door, the second binding being useful for translating subsequent communication messages sent between the first and second endpoints.

20. A NAT system as recited in claim 19, wherein at least one of the processors and memory are further adapted to dismantle the registration door and its associated first binding if a timer associated with the registration message expires or if an unregistration message is received from the first endpoint node.

36. A NAT system as recited in claim 11, wherein the first and second bindings are dismantled so that their global information can be used by other endpoint nodes.

21. A computer program product for managing a registration state of an endpoint node in a network address port translation environment, the computer program product comprising:

at least one computer readable storage medium;

computer program instructions stored within the at least one computer readable storage medium product configured to;

at a network address translation device, receive a registration message from a first endpoint node located within a local network, the registration message being sent from the first endpoint node to a gatekeeper node, wherein the registration message includes a local source address of the first endpoint node, a first local source port of the first endpoint node, and local call signaling information;

at the network address translation device, translate the local source address and/or the first local source port of the first endpoint node into a first global address and/or a first global port, respectively;

at the network address translation device, create a first binding that associates the local source address with the global source address and/or associates the first local source port with the first global port;

at the network address translation device, translate the local call signaling information into global call signaling information;

at the network address translation device, create a second binding between the local call signaling information and the global call signaling information such that the second binding associates different local and global information than the first binding, wherein creating the first and second bindings is based on the registration message that was received at the network translation device; and

if an unregistration message is received from the first endpoint node, dismantle the first binding and the second binding at the network address translation device.

22. A computer program product as recited in claim 21, wherein the second binding associates a second local source port of the local call signaling information with a second global port and wherein the second local source port differs from the first local port and the second global port differs from the first global port and wherein the local source address and first local source port are translated into the first global address and the first global port, respectively, and wherein the first global address and port and the second global source port can be used by another endpoint node to communicate with the first endpoint node.

23. A computer program product as recited in claim 22, wherein the local call signaling information is within the payload of the registration message and further includes the local source address.

24. A computer program product as recited in claim 21, wherein the computer program instructions are further configured to:

setting a timer based on a time period associated with the registration message;

restarting the timer when a refresh message is received from the first endpoint node, and

dismantle the first and second binding if the timer expires.

25. A computer program product as recited in claim 24, wherein creating the second binding includes creating a registration door containing the global call signaling information and the time period after which the registration of the first endpoint node is to expire, the time period originating from within the local call signaling information, and dismantling the second binding is further accomplished by dismantling the registration door if the timer expires or if an unregistration message is received from the first endpoint node.

26. A computer program product as recited in claim 25, wherein the first binding is an entry within a NAT Table and the registration door is an entry within a Registration Table.

27. A computer program product as recited in claim 21, wherein the computer program instructions are further configured to:

creating a registration door containing the global call signaling information and a time period after which the registration of the first endpoint node is to expire, the time period originating from within the local call signaling information; and

associating the registration door with the first binding.

28. A computer program product as recited in claim 27, wherein associating the registration door with the first binding is accomplished by forming a link there between the registration door and the first binding.

29. A computer program product as recited in claim 27, wherein the computer program instructions are further configured to

receive a communication message from a second endpoint node destined for the first endpoint node, the communication message being a first message to establish a data connection between the second and first endpoint, the communication message having a second source address, a second destination address, a second source port, and a second destination port, wherein the second destination address equals the first global address and the second destination port equals a first global port obtained from the global call signaling information;

translate the communication message based on the registration door; and

wherein creation of the second binding is based on the registration door, the second binding being useful for translating subsequent communication messages sent between the first and second endpoints.

30. A computer program product as recited in claim 29, wherein the computer program instructions are further configured to dismantle the registration door and its associated first binding if a timer associated with the registration message expires or if an unregistration message is received from the first endpoint node.

31. An apparatus for managing a registration state of an endpoint node in a network address port translation environment, the apparatus comprising:

means for receiving a registration message from a first endpoint node located within a local network, the registration message being sent from the first endpoint node to a gatekeeper node, wherein the registration message includes a local source address of the first endpoint node, a first local source port of the first endpoint node, and local call signaling information

means for translating the local source address and/or the first local source port of the first endpoint node into a first global address and/or a first global port, respectively;

means for creating a first binding that associates the local source address with the global source address and/or associates the first local source port with the first global port;

means for translating the local call signaling information into global call signaling information;

means for creating a second binding between the local call signaling information and the global call signaling information such that the second binding associates different local and global information than the first binding, wherein creating the first and second bindings is based on the registration message that was received at the network translation device; and

means for dismantling the first binding and the second binding if an unregistration message is received from the first endpoint node.

32. An apparatus as recited in claim 31, further comprising:

means for creating a registration door containing the global call signaling information and a time period after which the registration of the first endpoint node is to expire, the time period originating from within the local call signaling information; and

means for associating the registration door with the first binding.

33. An apparatus as recited in claim 32, further comprising:

means for receiving a communication message from a second endpoint node destined for the first endpoint node, the communication message being a first message to establish a data connection between the second and first endpoint, the communication message having a second source address, a second destination address, a second source port, and a second destination port, wherein the second destination address equals the first global address and the second destination port equals a first global port obtained from the global call signaling information;

means for translating the communication message based on the registration door; and

wherein creation of the second binding is based on the registration door, the second binding being useful for translating subsequent communication messages sent between the first and second endpoints.

34. An apparatus as recited in claim 33, further comprising means for dismantling the registration door and its associated first binding if a timer associated with the registration message expires or if an unregistration message is received from the first endpoint node.