VoIP over access network

• US 7,545,823 B1
• Filed: 03/16/2006
• Issued: 06/09/2009
• Est. Priority Date: 07/31/2001
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Zhao, Jiabin
• Primary Examiner(s): Chan; Wing F
• Assistant Examiner(s): Mais; Mark A
• Application Number:
  US11/377,955
• Time in Patent Office: 1,181 Days
• Field of Search: 370/352, 370/395.1, 370/401, 370/524, 370/353, 370/354, 370/355, 370/356, 370/395.2, 370/395.21, 370/395.5, 370/395.51, 370/395.52, 370/395.6, 370/465, 370/466
• US Class Current: 370/401
• CPC Class Codes: H04L 65/103 in the network
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04L 65/1043 Gateway controllers, e.g. media gateway control protocol [MGCP] controllers
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04M 7/122 where the PSTN/ISDN access is used as an access to networks other than PSTN/ISDN access arrangements to networks other than PSTN/ISDN H04M7/0066; access arrangements to public data networks H04L12/2856

Abstract

A system and method are disclosed for controlling access networks directly via a packet network gateway that is itself controlled by a remote call agent. In one embodiment, the gateway performs translation between access network protocol signaling and gateway control protocol messaging such that, to the call agent, the gateway appears to be physically connected to a group of subscribers directly, and to the access network, the gateway appears to function as a circuit-switched network. In one application, a gateway according to the present invention thus allows existing access network devices to connect directly to a packet network without having to pass through an intervening PSTN circuit switch.

Claims

1. A gateway, comprising:

a packet data port configured to connect to and communicate with a packet-switched network;

an access network interface configured to connect to and communicate with an access network, wherein said access network aggregates received data and signaling from a plurality of subscriber devices on a trunk extending directly to the access network interface; and

a processor configured to;

exchange signaling, using an access network protocol, with an access network device connected to the access network interface;

exchange signaling packets, using a packet-based gateway control protocol and the packet data port, with a call agent reachable over the packet-switched network; and

translate signaling between the access network protocol and the packet-based gateway control protocol, such that the gateway emulates a group of physical subscriber connections to the access network device, and such that the gateway controls the access network device based on commands in signaling packets issued by the call agent.

2. The gateway of claim 1, wherein the processor is further configured to:

translate an access network protocol establishment request received over the access network interface into a packet-based gateway control protocol communication and send the packet-based gateway control protocol communication over the packet data port to the call agent;

receive back a call allocation authorization from the call agent over the packet data port; and

send an access network protocol notification over the access network interface indicating authorization for the access network protocol establishment request, said access network protocol notification sent to the access network device.

3. The gateway of claim 2, wherein said received access network protocol establishment request is generated in response to an off-hook condition detected at the access network device.

4. The gateway of claim 2, wherein the packet data port further receives back a command request in response to said translation, the command request commanding the gateway to collect values for digits dialed by a subscriber.

5. The gateway of claim 1, wherein said access network protocol comprises V5 and said gateway control protocol comprises Media Gateway Control Protocol (MGCP).

6. The gateway of claim 2, wherein said access network protocol notification is configured to cause the access network device to send back an allocation complete command and transmit a dialtone to a subscriber.

7. A gateway, comprising:

a packet data port configured to connect to and communicate with a packet-switched network;

an access network interface configured to connect to and communicate with an access network, wherein said access network terminates subscriber lines; and

circuitry configured to;

exchange signaling, using an access network protocol, with an access network device of the access network;

exchange signaling packets, using a packet-based gateway control protocol and the packet data port, with a call agent reachable over the packet-switched network; and

translate signaling between the access network protocol and the packet-based gateway control protocol, such that the gateway emulates a group of physical subscriber connections to the access network device, and such that the gateway controls the access network device based on commands in signaling packets issued by the call agent.

8. The gateway of claim 7, wherein a trunk physically connects the access network device to the access network interface.

9. The gateway of claim 8, wherein said trunk is physically terminated by the access network interface.

10. The gateway of claim 7, wherein the gateway and the call agent emulate a Publicly Switched Telephone Network (PSTN) switching point to the access network device.

11. A computer-readable medium storing instructions that, if executed, result in:

exchanging signaling, using an access network protocol, with an access network device that terminates subscriber lines;

exchanging signaling packets, using a packet-based gateway control protocol, between gateway for a packet-switched network and a call agent operating in the packet-switched network; and

translating signaling between the access network protocol and the packet-based gateway control protocol, such that the gateway emulates a group of physical subscriber connections to the access network device, and such that the gateway controls the access network device based on commands in signaling packets issued by the call agent.

12. The computer-readable medium of claim 11, wherein said access network signaling is transmitted over a trunk that is not part of the Publicly Switched Telephone Network (PSTN).

13. The computer-readable medium of claim 12, wherein said signaling is exchanged over a gateway voice data port.

14. A gateway, comprising:

means for exchanging signaling, using an access network protocol, with an access network device that terminates subscriber lines;

means for exchanging signaling packets, using a packet-based gateway control protocol, between the gateway and a call agent operating in a packet-switched network; and

means for translating signaling between the access network protocol and the packet-based gateway control protocol, such that the gateway emulates a group of physical subscriber connections to the access network device, and such that the gateway controls the access network device based on commands in signaling packets issued by the call agent.

15. The gateway of claim 14, wherein the gateway and the call agent emulate a Publicly Switched Telephone Network (PSTN) switching point to the access network device.