Internet protocol transport of PSTN-to-PSTN telephony services

• US 20040246949A1
• Filed: 07/13/2004
• Published: 12/09/2004
• Est. Priority Date: 06/14/1999
• Status: Active Grant

• Current Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Original Assignee: MCI WorldCom, Inc. (Verizon Communications Inc.)
• Inventors: Cannon, Matthew J.
• Granted Patent: US 7,653,081 B2
• Time in Patent Office: Days
• US Class Current: 370/352
• CPC Class Codes: H04L 65/103 in the network
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04L 65/1083 In-session procedures
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/168 specially adapted for link layer protocols, e.g. asynchronous transfer mode [ATM], synchronous optical network [SONET] or point-to-point protocol [PPP]
• CPC Class Codes: H04L 69/169 Special adaptations of TCP, UDP or IP for interworking of IP based networks with other networks protocols for interworking, protocol conversion H04L69/08
• CPC Class Codes: H04M 7/1295 Details of dual tone multiple frequency signalling
• CPC Class Codes: H04Q 3/0025 Provisions for signalling

Abstract

A system for transporting public switched network (PSTN) terminated signaling across an Internet protocol (IP) network includes a gateway between the PSTN and the IP network. The gateway receives a telephony signaling message from the PSTN and determines if the telephony signaling message maps to an IP signaling message. If the telephony signaling message does not map to an IP signaling message, the gateway packages the telephony signaling message in a special IP signaling message for transport over the IP network. If the gateway receives a special IP signaling special message, the gateway unpackages the telephony signaling message from the special message for transport over the PSTN. If the gateway receives DTMF signals from the PSTN, the gateway translates the DTMF signals to digits and packages the digits in a special IP signaling message for transport over the IP network. The gateway also packages the DTMF signals in an IP media transport protocol message for transport over the IP network.

Claims

1. A method of transporting calls across an Internet protocol network, the method comprising:

receiving a telephony signaling message at an Internet telephony gateway;

determining if the telephony signaling message maps to an Internet protocol signaling message; and

if the telephony signaling message does not map to the Internet protocol signaling message, packaging the telephony signaling message in an Internet protocol signaling special message for transport over the Internet protocol network, the Internet protocol signaling special message including a session initiation protocol (SIP) informational message.

2. The method of claim 1, wherein the SIP informational message is a post-session establishment SIP control message.

3. The method as claimed in claim 1, further comprising:

receiving the Internet protocol signaling special message at a second Internet telephony gateway; and

unpackaging the telephony signaling message from the Internet protocol signaling special message for transport over a public switched telephone network.

4. The method as claimed in claim 1, wherein the telephony signaling protocol is SS7.

5. The method as claimed in claim 4, wherein the telephony signaling protocol message is an ISUP message.

6. The method of claim 1, further comprising:

receiving dual-tone frequency (DTMF) signals at the gateway;

translating the DTMF signals to digits; and

packaging the digits in an Internet protocol signaling special message for transport over the Internet protocol network.

7. The method as claimed in claim 6, comprising packaging the DTMF signals in an Internet protocol media transport message for transport over the Internet protocol network.

8. A telecommunications system gateway, comprising:

a signaling gateway adapted to translate telephony signaling messages to Internet protocol signaling messages, the signaling gateway including means for packaging a telephony signaling message that does not map to an Internet protocol signaling message in an Internet protocol special signaling message, the Internet protocol special signaling message including a post-session establishment session initiation protocol (SIP) informational message; and

a media gateway adapted to translate telephony media to Internet protocol media.

9. The gateway as claimed in claim 8, wherein the signaling gateway includes means for unpacking a telephony signaling message from the Internet protocol special signaling message.

10. The gateway as claimed in claim 8, wherein the media gateway comprises means for packaging DTMF signals in an Internet media transport protocol message.

11. The gateway as claimed in claim 10, wherein the media gateway further comprises means for unpackaging DTMF signals from Internet protocol media transport messages.

12. The gateway claimed as in claim 10, wherein the gateway further comprises:

means for translating dual-tone multi-frequency (DTMF) signals to digits; and

means for providing the digits to the signaling gateway.

13. The gateway as claimed in claim 12, wherein the signaling gateway comprises means for packaging the digits in the special Internet protocol signaling message.

14. A telecommunications system comprising:

an Internet telephony gateway operably connected between a first public switched telephone network and an Internet protocol network, the telephony gateway including;

means for mapping telephony signaling messages to Internet protocol signal messages; and

means for packaging a telephony signaling message that does not map to an Internet protocol signaling message in a special Internet protocol signaling message for transport over the Internet protocol network, the special Internet protocol signaling message including a session initiation protocol (SIP) informational message; and

a second Internet telephony gateway operably connected between the Internet protocol network and a second public switched telephone network, the second telephony gateway including;

means for mapping Internet protocol signaling messages to telephony signal messages; and

means for unpacking the special Internet protocol signaling messages for transport over the second public switched telephone network.

15. The system of claim 14, wherein the SIP informational message is a post-session establishment SIP control message.

16. The system as claimed in claim 14, wherein the telephony signaling protocol is SS7.

17. The system as claimed in claim 16, wherein the telephony signaling protocol messages are ISUP messages.

18. The system as claimed in claim 14, wherein the telephony gateway comprises:

means for translating dual-tone multi-frequency (DTMF) signals to digits; and

means for packaging the digits in the Internet protocol signaling special message for transport over the Internet protocol network.

19. The system as claimed in claim 18, wherein the telephony gateway further comprises means for packaging DTMF signals in an Internet protocol media transport message for transport over the Internet protocol network.

20. A method for transporting calls across a network comprising:

receiving a first telephony signaling message, at a gateway, during a telephony session;

determining if the first telephony signaling message maps to an Internet protocol signaling message;

translating the first telephony signaling message to an Internet protocol signaling message for transport over the network based on the first telephony signaling message mapping to the Internet protocol signaling message;

receiving a second telephony signaling message, at the gateway, during the session;

determining if the second telephony signaling message maps to the Internet protocol signaling message; and

packaging the second telephony signaling message in an Internet protocol signaling special message for transport over the Internet protocol network based on the second telephony signaling message not mapping to the Internet protocol signaling message, the Internet protocol signaling special message including a session initiation protocol (SIP) informational message.

21. The method of claim 20, wherein the SIP informational message is a post-session establishment SIP control message.

22. The method recited in claim 21 further comprising:

receiving a dual-tone multi-frequency (DTMF) signal, at the Internet gateway, during the session;

translating the DTMF signal to a digit; and

packaging the digit in an the Internet protocol signaling special message and translating the DTMF signal to an Internet protocol media transport message for transport over the Internet protocol network.

23. A method for transporting calls across an Internet-protocol network comprising:

receiving an Internet protocol signaling message, at a gateway, during a telephony session;

receiving an Internet protocol signaling special message, at the Internet gateway, during the session, the Internet protocol signaling special message including a session initiation protocol (SIP) informational message; and

unpacking a telephony signaling message from the Internet protocol signaling special message for transport over a public switched telephone network.

24. The method recited in claim 23 further comprises:

receiving a second Internet protocol signaling special message, at the Internet gateway, during the session;

unpacking a digit from the Internet protocol signaling special message; and

translating the digit to a dual-tone multi-frequency (DTMF) signal.

25. A telecommunications device comprising:

an Internet telephony signaling gateway adapted to translate a telephony signaling message to an Internet protocol signaling message when the telephony signaling message maps to an Internet protocol signaling message and adapted to package a telephony signaling message that does not map to an Internet protocol signaling message to an Internet protocol signaling special message that includes the telephony signaling message as an argument of the signaling special message.

26. The device of claim 25, wherein the Internet protocol signaling special message is a post-session establishment session initiation protocol (SIP) control message.

27. The system recited in claim 25, wherein the Internet telephony signaling gateway is a bidirectional Internet telephony signaling gateway adapted to translate an Internet protocol signaling message to a telephony signaling message and further wherein the Internet telephony signaling gateway adapted to unpackage a telephony signaling message from an Internet protocol signaling special message.

28. The system recited in claim 25, wherein the telephony signaling is formatted in signaling system 7 (SS7) protocol and the telephony signaling message is an integrated services user part (ISUP) message.

29. The method recited in claim 25, wherein the Internet telephony gateway is further adapted to translate a dual-tone multi-frequency (DTMF) signal to a digit and package the digit in a the Internet protocol signaling special message, the device further comprising:

an Internet telephony media gateway adapted to translate the DTMF signal to a an Internet protocol media transport message.

30. The method recited in claim 29, wherein the Internet telephony signaling gateway is further adapted to package the digit in the Internet protocol signaling special message.

31. A method comprising:

receiving a dual-tone multi-frequency (DTMF) signal, at an Internet protocol gateway, during a telephony session;

translating the DTMF signal to at least one digit;

generating a post-session establishment session initiation protocol (SIP) control message that includes the at least one digit;

transmitting the SIP control message over an Internet protocol network; and

transmitting an Internet protocol media transport message that includes the DTMF signal over the Internet protocol network.