Method for providing voice-over-IP service

• US 7,406,043 B1
• Filed: 04/10/2007
• Issued: 07/29/2008
• Est. Priority Date: 11/13/2001
• Status: Expired due to Fees

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Murray, John F, Chu, Yue-Chuan, Hua, Ningming
• Primary Examiner(s): Backer; Firmin
• Assistant Examiner(s): NGUYEN, PHUONGCHAU BA
• Application Number:
  US11/733,641
• Time in Patent Office: 476 Days
• Field of Search: None
• US Class Current: 370/230
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/2564 for a higher-layer protocol, e.g. for session initiation protocol [SIP]
• 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]

Abstract

A system and method, e.g., Voice Proxy Server (VPS), is described for managing Voice over IP (VoIP) services between a NAT enabled private network and a public network such as the Internet. The VPS acts like the Call Agent to the nodes in the private network and it represents an embedded voice client to the real Call Agent in the public network. Each logical line of the VPS corresponds to a real voice line in the private node. VoIP signaling messages may be carried in the payload of the IP packets. VPS will properly translate IP address and/or port number information in the payload to correctly route the signaling data between networks. Additionally, VPS will forward the incoming Real Time Protocol (RTP) packets to the real destination in the private network.

Claims

1. A method for managing network services between a plurality of networks comprising:

receiving at a Voice Proxy Server (VPS) an Internet Protocol data packet with a corresponding source address from a first network, wherein the Internet Protocol data packet comprises a header and a payload and the payload of said Internet Protocol data packet contains at least a portion of a destination address;

translating the destination address, wherein the translating comprises;

receiving a first endpoint identifying parameter corresponding to a private network node;

checking a mapping table for the first endpoint identifying parameter;

allocating a logical line number to create a VPS endpoint identifying parameter based on said checking, wherein the VPS endpoint identifying parameter comprises the logical line number and VPS IP address;

saving a mapping of the first endpoint identifying parameter and the VPS endpoint identifying parameter in the mapping table; and

replacing the first endpoint identifying parameter with the VPS endpoint identifying parameter; and

delivering the Internet Protocol data packet to a destination node on a second network based on said translating.

2. The method of claim 1, wherein the Internet Protocol data packet carries Voice-over-IP (VoIP) protocol messages.

3. The method of claim 2, wherein the VoIP protocol is one of Media Gateway Controller Protocol (MGCP)/Network-based Call signaling (NCS) protocol and Session Initiation Protocol (SIP).

4. The method of claim 3, wherein the VoIP protocol is MGCP/NCS.

5. The method of claim 4, wherein the VoIP protocol provides call control.

6. The method of claim 1, wherein the first network is a public network and the second network is a private network, said private network comprising a plurality of local nodes.

7. The method of claim 1, wherein the first network is a private network comprising a plurality of local nodes and the second network is a public network.

8. The method of claim 1, wherein said translating further comprises:

receiving a first parameter corresponding to a Call Agent of a public network;

saving the first parameter corresponding to the Call Agent; and

replacing the first parameter corresponding to the Call Agent with a second parameter, the second parameter corresponding to the VPS.

9. The method of claim 1, wherein the first endpoint identifying parameter represents a group of endpoints and the translating further comprises:

querying the number of endpoints associated with the private network node.

10. The method of claim 1, wherein said translating further comprises sending a NACK response based on said checking.

11. The method of claim 1, wherein the first endpoint identifying parameter comprises a VPS endpoint.

12. The method of claim 11, wherein said translating further comprises:

receiving a first parameter corresponding to a Call Agent of a public network;

saving the first parameter corresponding to the Call Agent; and

replacing the first parameter corresponding to the call Agent with a second parameter, the second parameter corresponding to the VPS.

13. The method of claim 11, further comprising:

receiving a Transaction Identifier from a private network node; and

retrieving a corresponding endpoint from the mapping table based on the Transaction Identifier.

14. The method of claim 13, further comprising modifying the mapping information.

15. The method of claim 1, wherein the first endpoint identifying parameter comprises a wild card representing one of a plurality of endpoints.

16. The method of claim 15, wherein the first parameter indicating a notified entity corresponding to the VPS.

17. The method of claim 15, further comprising:

receiving a Transaction Identifier from a private network node; and

retrieving a corresponding endpoint from the mapping table based on the Transaction Identifier.

18. The method of claim 1, wherein said delivering comprises sending modified signaling messages from private network nodes to a Call Agent in a public network.

19. The method of claim 1, wherein said delivering comprises sending modified signaling messages from a Call Agent in a public network to a desired private network node wherein the IP address of the private network node is retrieved from the mapping table.