System and method for performing IP telephony including internal and external call sessions

• US 20020150083A1
• Filed: 07/11/2001
• Published: 10/17/2002
• Est. Priority Date: 04/03/2001
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: VoxPath Networks, Inc (IPNav)
• Inventors: Preston, Jason D., Fangman, Richard E.
• Granted Patent: US 7,068,646 B2
• Time in Patent Office: Days
• US Class Current: 370/352
• 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 61/2517 using port numbers
• CPC Class Codes: H04L 61/2546 Arrangements for avoiding unnecessary translation
• CPC Class Codes: H04L 61/2564 for a higher-layer protocol, e.g. for session initiation protocol [SIP]
• CPC Class Codes: H04L 61/2578 without involvement of the NAT server
• CPC Class Codes: H04L 63/0272 Virtual private networks
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/20 for managing network security; network security policies in general filtering policies H04L63/0227
• CPC Class Codes: H04L 65/1043 Gateway controllers, e.g. media gateway control protocol [MGCP] controllers
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/65 Network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP]
• CPC Class Codes: H04M 7/006 Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04M 7/1285 Details of finding and selecting a gateway for a particular call

Abstract

System and method for IP telephony including internal and external call sessions. The system includes at least one IP telephone (IPT), a Service Gateway (SG), and a Media Gateway Controller (MGC). The SG receives a Call Setup request, including a source IP address and a destination telephone number. A first Media Gateway is selected based on the source IP address. A second Media Gateway is selected based on the destination telephone number. A public IP address of the first Media Gateway is compared to a public IP address of the second Media Gateway, and if the same, respective private IP addresses of the first and second Media Gateway are selected for Call Setup. If different, the respective public IP addresses of the first and second Media Gateway are selected for Call Setup. Thus, the system and method distinguish between external and internal call sessions and route the IP traffic accordingly.

Claims

1. A method for performing IP telephony, comprising:

receiving a Call Setup request, wherein the Call Setup request comprises a source IP address and a destination telephone number;

selecting a first Media Gateway based on the source IP address;

selecting a second Media Gateway based on the destination telephone number;

comparing a public IP address of the first Media Gateway to a public IP address of the second Media Gateway;

if the public IP address of the first Media Gateway is the same as the public IP address of the second Media Gateway, selecting a private IP address of the first Media Gateway and a private IP address of the second Media Gateway for Call Setup; and

if the public IP address of the first Media Gateway is not the same as the public IP address of the second Media Gateway, selecting the public IP address of the first Media Gateway and the public IP address of the second Media Gateway for Call Setup.

2. The method of claim 1, further comprising:

sending the selected IP address of the first Media Gateway to the second Media Gateway; and

sending the selected IP address of the second Media Gateway to the first Media Gateway.

3. The method of claim 2, further comprising:

the first Media Gateway sending data to the second Media Gateway using the selected IP address of the second Media Gateway; and

the second Media Gateway sending data to the first Media Gateway using the selected IP address of the first Media Gateway.

4. The method of claim 1, further comprising:

registering the first Media Gateway prior to said receiving, wherein said registering the first Media Gateway comprises receiving and storing the public IP address of the first Media Gateway; and

registering the second Media Gateway prior to said receiving, wherein said registering the second Media Gateway comprises receiving and storing the public IP address of the second Media Gateway.

5. The method of claim 4, wherein said registering the first Media Gateway further comprises receiving and storing a private IP address of the first Media Gateway.

6. The method of claim 4, wherein said registering the second Media Gateway further comprises receiving and storing a private IP address of the second Media Gateway.

7. The method of claim 1, wherein the first Media Gateway and the second Media Gateway each comprise one of an IP telephone or a Trunking Gateway, wherein the Trunking Gateway comprises an interface to the Public Switched Telephone Network (PSTN).

8. A system for performing IP telephony, comprising:

a network;

a first Media Gateway;

a second Media Gateway, wherein the second Media Gateway is operable to couple to the first Media Gateway through the network; and

a Media Gateway Controller, wherein the Media Gateway Controller is operable to couple to the first Media Gateway and the second Media Gateway through the network;

wherein the first Media Gateway is operable to send a Call Setup request to the Media Gateway Controller, wherein the Call Setup request comprises a source IP address and a destination telephone number;

wherein the Media Gateway Controller is operable to;

receive a Call Setup request;

select a first Media Gateway based on the source IP address;

select a second Media Gateway based on the destination telephone number;

compare a public IP address of the first Media Gateway to a public IP address of the second Media Gateway;

if the public IP address of the first Media Gateway is the same as the public IP address of the second Media Gateway, select a private IP address of the first Media Gateway and a private IP address of the second Media Gateway for Call Setup; and

if the public IP address of the first Media Gateway is not the same as the public IP address of the second Media Gateway, select the public IP address of the first Media Gateway and the public IP address of the second Media Gateway for Call Setup.

9. The system of claim 8, wherein the Media Gateway Controller is further operable to:

send the selected IP address of the first Media Gateway to the second Media Gateway; and

send the selected IP address of the second Media Gateway to the first Media Gateway.

10. The system of claim 9,

wherein the first Media Gateway is operable to send data to the second Media Gateway using the selected IP address of the second Media Gateway;

and

wherein the second Media Gateway is operable to send data to the first Media Gateway using the selected IP address of the first Media Gateway.

11. The system of claim 8, wherein the Media Gateway Controller is further operable to:

register the first Media Gateway prior to said receiving, wherein, in registering the first Media Gateway the Media Gateway Controller is operable to receive and store the public IP address of the first Media Gateway; and

register the second Media Gateway prior to said receiving, wherein, in registering the second Media Gateway the Media Gateway Controller is operable to receive and store the public IP address of the second Media Gateway.

12. The system of claim 11, wherein, in registering the first Media Gateway the Media Gateway Controller is further operable to receive and store a private IP address of the first Media Gateway.

13. The system of claim 11, wherein, in registering the second Media Gateway the Media Gateway Controller is further operable to receive and store a private IP address of the second Media Gateway.

14. The system of claim 8, wherein the first Media Gateway and the second Media Gateway each comprise one of an IP telephone or a Trunking Gateway, wherein the Trunking Gateway comprises an interface to the Public Switched Telephone Network (PSTN).

16. The memory medium of claim 15, wherein the program instructions are further executable to perform:

sending the selected IP address of the first Media Gateway to the second Media Gateway; and

sending the selected IP address of the second Media Gateway to the first Media Gateway.

17. The memory medium of claim 16,

wherein the selected IP address of the second Media Gateway is useable by the first Media Gateway to send data to the second Media Gateway;

and

wherein the selected IP address of the first Media Gateway is useable by the second Media Gateway to send data to the first Media Gateway.

18. The memory medium of claim 15, wherein the program instructions are further executable to perform:

registering the first Media Gateway prior to said receiving, wherein said registering the first Media Gateway comprises receiving and storing the public IP address of the first Media Gateway; and

registering the second Media Gateway prior to said receiving, wherein said registering the second Media Gateway comprises receiving and storing the public IP address of the second Media Gateway.

19. The memory medium of claim 18, wherein said registering the first Media Gateway further comprises receiving and storing a private IP address of the first Media Gateway.

20. The memory medium of claim 18, wherein said registering the second Media Gateway further comprises receiving and storing a private IP address of the second Media Gateway.

21. The memory medium of claim 15, wherein the first Media Gateway and the second Media Gateway each comprise one of an IP telephone or a Trunking Gateway, wherein the Trunking Gateway comprises an interface to the Public Switched Telephone Network (PSTN).

15. A memory medium, wherein the memory medium stores program instructions which are executable to perform:

receiving a Call Setup request, wherein the Call Setup request comprises a source IP address and a destination telephone number;

selecting a first Media Gateway based on the source IP address;

selecting a second Media Gateway based on the destination telephone number;

comparing a public IP address of the first Media Gateway to a public IP address of the second Media Gateway;

if the public IP address of the first Media Gateway is the same as the public IP address of the second Media Gateway, selecting a private IP address of the first Media Gateway and a private IP address of the second Media Gateway for Call Setup; and

if the public IP address of the first Media Gateway is not the same as the public IP address of the second Media Gateway, selecting the public IP address of the first Media Gateway and the public IP address of the second Media Gateway for Call Setup.