System, method, and computer program product for resolving addressing in a network including a network address translator

• US 7,797,433 B2
• Filed: 06/29/2001
• Issued: 09/14/2010
• Est. Priority Date: 06/30/2000
• Status: Expired due to Fees

• Current Assignee: Net2phone
• Original Assignee: Net2phone
• Inventors: Kennedy, Thomas Scott, Skelton, Jeffrey S., Goldberg, Harold Jeffrey, Galinsky, Estie, Staniforth, Alan
• Primary Examiner(s): Ismail; Shawki S
• Application Number:
  US10/311,324
• Publication Number:
  US 20040252683A1
• Time in Patent Office: 3,364 Days
• Field of Search: 709223-229, 709/245, 370/389, 370/352
• US Class Current: 709/229
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/106 across networks, e.g. mapping telephone numbers to data network addresses
• CPC Class Codes: H04L 61/25 of the same type
• CPC Class Codes: H04L 61/2564 for a higher-layer protocol, e.g. for session initiation protocol [SIP]
• CPC Class Codes: H04L 61/2567 for reachability, e.g. inquiring the address of a correspondent behind a NAT server
• CPC Class Codes: H04L 61/2575 using address mapping retrieval, e.g. simple traversal of user datagram protocol through session traversal utilities for NAT [STUN]
• CPC Class Codes: H04L 61/2578 without involvement of the NAT server
• CPC Class Codes: H04L 61/2585 through application level gateway [ALG]
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A system, method, and computer program product through which address resolution is performed for nodes (101, 103) of a network that are behind a network address translator (NAT). A determination is made upon the initiation of a communication session as to whether one or more of the nodes (101, 103) included in the session are behind a NAT. Based on the determination, information is exchanged (L102, L103) from an independent application server (105) to the nodes (101, 103) included in the session so as to resolve the addressing problems introduced by the NAT. The invention is applicable in applications including, but not limited to, IP telephony, and applications complying with the session initiation protocol (SIP).

Claims

1. A computer implemented method for performing address resolution, comprising the steps of:

sending a first initiate message by a controller to a first node, the first initiate message telling the first node to send a first special message to the controller at a first predetermined address, the first node being behind a first network address translator;

sending a second initiate message by the controller to a second node, the second initiate message telling the second node to send a second special message to the controller at a second predetermined address, the second node being behind a second network address translator;

sending the first special message by the first node to the controller at the first predetermined address;

sending the second special message by the second node to the controller at the second predetermined address;

determining by the controller a first external address of the first node based on information received by the controller with the first special message;

determining by the controller a second external address of the second node based on information received by the controller with the second special message;

sending a third initiate message by the controller to the first node, the third initiate message telling the first node to send another first special message to the controller at a third predetermined address;

sending a fourth initiate message by the controller to the second node, the fourth initiate message telling the second node to send another second special message to the controller at a fourth predetermined address;

sending the another first special message by the first node to the controller at the third predetermined address;

sending the another second special message by the second node to the controller at the fourth predetermined address;

determining by the controller another first external address of the first node based on information received by the controller with the another first special message;

determining by the controller another second external address of the second node based on information received by the controller with the another second special message;

determining by the controller that none of the first network address translator and the second network address translator base an address translation on a destination of a message sent;

sending a route message by the controller to the first node, the route message including a second communication address of the second node, the second communication address being the second external address of the second node; and

sending another route message by the controller to the second node, the another route message including a first communication address of the first node, the first communication address being the first external address of the first node;

wherein the first external address of the first node, the another first external address of the first node, the second external address of the second node and the another second external address of the second node comprise an Internet protocol address and a user datagram protocol port.

2. The method of claim 1, further comprising the step of:

determining by the controller that the first node is behind a first network address translator, and that the second node is behind a second network address translator.

3. The method of claim 2, wherein the determining step comprises:

receiving by the controller a first address message from the first node, the first address message including a first internal address corresponding to the first node;

receiving by the controller a second address message from the second node, the second address message including a second internal address corresponding to the second node;

comparing by the controller the first internal address with a first source address included with the first address message, and the second internal address with a second source address included with the second address message; and

determining by the controller based on a result of the comparing step that the first node is behind a first network address translator, and that the second node is behind a second network address translator.

4. The method of claim 1, further comprising the steps of:

sending a first acknowledgement message by the controller to the first node after receiving the first special message;

sending a second acknowledgement message by the controller to the second node after receiving the second special message;

ending a third acknowledgement message by the controller to the first node after receiving the another first special message;

sending a fourth acknowledgement message by the controller to the second node after receiving the another second special message, wherein

the sending the first special message step comprises repeatedly sending the first special message by the first node until the first node receives the first acknowledgement message,

the sending the second special message step comprises repeatedly sending the second special message by the second node until the second node receives the second acknowledgement message,

the sending the another first special message step comprises repeatedly sending the another first special message by the first node until the first node receives the third acknowledgement message, and

the sending the another second special message step comprises repeatedly sending the another second special message by the second node until the second node receives the fourth acknowledgement message.

5. The method of claim 4, wherein the initiate messages, the special messages, the route messages, and the acknowledgement messages comprise Internet protocol messages.

6. The method of claim 5, wherein:

the initiate messages, the route messages, and the acknowledgement messages comprise transmission control protocol/Internet protocol messages, and the special messages comprise a user datagram protocol/Internet protocol message.

7. The method of claim 1, wherein the initiate messages, the special messages, and the route messages comprise Internet protocol messages.

8. The method of claim 7, wherein:

the initiate messages and the route messages comprise transmission control protocol/Internet protocol messages, and the special messages comprise a user datagram protocol/Internet protocol message.

9. The method of claim 1, wherein the controller is a process independent of the first node and the second node.

10. A computer implemented method for performing address resolution, comprising the steps of:

determining by a controller that a first node is behind a first network address translator and a second node is behind a second network address translator; and

performing address resolution by the controller, the performing step comprising;

sending a first initiate message by the controller to the first node, the first initiate message telling the first node to send a first special message to the controller at a first predetermined address,

sending a second initiate message by the controller to the second node, the second initiate message telling the second node to send a second special message to the controller at a second predetermined address,

sending the first special message by the first node to the controller at the first predetermined address,

sending the second special message by the second node to the controller at the second predetermined address,

determining by the controller a first external address of the first node based on information received by the controller with the first special message,

determining by the controller a second external address of the second node based on information received by the controller with the second special message,

sending a third initiate message by the controller to the first node, the third initiate message telling the first node to send another first special message to the controller at a third predetermined address,

sending a fourth initiate message by the controller to the second node, the fourth initiate message telling the second node to send another second special message to the controller at a fourth predetermined address,

sending the another first special message by the first node to the controller at the third predetermined address,

sending the another second special message by the second node to the controller at the fourth predetermined address,

determining by the controller another first external address of the first node based on information received by the controller with the another first special message,

determining by the controller another second external address of the second node based on information received by the controller with the another second special message,

determining by the controller that none of the first network address translator and the second network address translator base an address translation on a destination of a message sent,

sending a route message by the controller to the first node, the route message including a second communication address of the second node, the second communication address being the second external address of the second node, and

sending another route message by the controller to the second node, the another route message including a first communication address of the first node, the first communication address being the first external address of the first node,

wherein the first external address of the first node, the another first external address of the first node, the second external address of the second node and the another second external address of the second node comprise an Internet protocol address and a user datagram protocol port.

11. A system for performing address resolution, comprising:

means for sending a first initiate message by a controller to a first node, the first initiate message telling the first node to send a first special message to the controller at a first predetermined address, the first node being behind a first network address translator;

means for sending a second initiate message by the controller to a second node, the second initiate message telling the second node to send a second special message to the controller at a second predetermined address, the second node being behind a second network address translator;

means for sending the first special message by the first node to the controller at the first predetermined address;

means for sending the second special message by the second node to the controller at the second predetermined address;

means for determining by the controller a first external address of the first node based on information received by the controller with the first special message;

means for determining by the controller a second external address of the second node based on information received by the controller with the second special message;

means for sending a third initiate message by the controller to the first node, the third initiate message telling the first node to send another first special message to the controller at a third predetermined address;

means for sending a fourth initiate message by the controller to the second node, the fourth initiate message telling the second node to send another second special message to the controller at a fourth predetermined address;

means for sending the another first special message by the first node to the controller at the third predetermined address;

means for sending the another second special message by the second node to the controller at the fourth predetermined address;

means for determining by the controller another first external address of the first node based on information received by the controller with the another first special message;

means for determining by the controller another second external address of the second node based on information received by the controller with the another second special message;

means for determining by the controller that none of the first network address translator and the second network address translator base an address translation on a destination of a message sent;

means for sending a route message by the controller to the first node, the route message including a second communication address of the second node, the second communication address being the second external address of the second node; and

means for sending another route message by the controller to the second node, the another route message including a first communication address of the first node, the first communication address being the first external address of the first node;

wherein the first external address of the first node, the another first external address of the first node, the second external address of the second node and the another second external address of the second node comprise an Internet protocol address and a user datagram protocol port.

12. The system of claim 11, further comprising:

means for determining by the controller that the first node is behind a first network address translator, and that the second node is behind a second network address translator.