Application for a voice over IP (VoIP) telephony gateway and methods for use therein

• US 20020101860A1
• Filed: 09/21/2001
• Published: 08/01/2002
• Est. Priority Date: 11/10/1999
• Status: Active Grant

• Current Assignee: Ribbon Communications Operating Company, Inc. (Ribbon Communications, Inc.)
• Original Assignee: Cheng Chen, Ki Choon Suh, Rajiv Bhatia, Timothy R Thornton
• Inventors: Chen, Cheng, Bhatia, Rajiv, Thornton, Timothy R., Suh, Ki Choon
• Granted Patent: US 6,665,293 B2
• Time in Patent Office: Days
• US Class Current: 370/352
• CPC Class Codes: H04L 12/14 Charging , metering or billing arrangements for data wireline or wireless communications
• CPC Class Codes: H04L 12/1403 Architecture for metering, charging or billing
• CPC Class Codes: H04L 12/1439 time-based
• CPC Class Codes: H04L 12/145 trading network capacity or selecting route based on tariff
• CPC Class Codes: H04L 12/1482 involving use of telephony infrastructure for billing for the transport of data, e.g. call detail record [CDR] or intelligent network infrastructure
• CPC Class Codes: H04L 12/1485 Tariff-related aspects
• CPC Class Codes: H04L 12/5692 Selection among different networks
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks
• CPC Class Codes: H04L 43/0829 Packet loss
• CPC Class Codes: H04L 43/0852 Delays
• CPC Class Codes: H04L 43/087 Jitter
• CPC Class Codes: H04L 43/16 Threshold monitoring
• CPC Class Codes: H04L 65/103 in the network
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1106 Call signalling protocols; H.323 and related
• CPC Class Codes: H04L 65/80 Responding to QoS
• 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: H04M 15/00 : Arrangements for metering, time-control or time indication ; Metering, charging or billing arrangements for voice wireline or wireless communications, e.g. VoIP
• CPC Class Codes: H04M 15/56 : for VoIP communications
• CPC Class Codes: H04M 15/8016 : based on quality of service [QoS]
• CPC Class Codes: H04M 15/8044 : Least cost routing
• CPC Class Codes: H04M 2215/202 : VoIP; Packet switched telephony
• CPC Class Codes: H04M 2215/42 : Least cost routing, i.e. provision for selecting the lowest cost tariff
• CPC Class Codes: H04M 2215/7414 : QoS
• CPC Class Codes: H04M 2215/745 : Least cost routing, e.g. Automatic or manual, call by call or by preselection
• CPC Class Codes: H04M 7/0069 : comprising a residential gateway, e.g. those which provide an adapter for POTS or ISDN terminals
• 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
• CPC Class Codes: H04M 7/125 : Details of gateway equipment
• CPC Class Codes: H04M 7/1295 : Details of dual tone multiple frequency signalling

Abstract

Apparatus, and accompanying methods for use therein, for a telephony gateway intended for use, e.g., paired use, at opposite ends of a data network connection, in conjunction with at each end, e.g., a private branch exchange (PBX) for automatically routing telephone calls, e.g., voice, data and facsimile, between two peer PBXs over either a public switched telephone network (PSTN) or a data network, based on, among other aspects, cost considerations for handling each such call and called directory numbers, monitoring quality of service (QoS) then provided through the data network and switching (“auto-switching”) such calls back and forth between the PSTN and the data network, as needed, in response to dynamic changes in the QoS such that the call is carried over a connection then providing a sufficient QoS. To support auto-switching, the apparatus embeds, using call independent signaling, certain call-specific information, as non-standard data, within various conventional H.323 messages that transit between the paired gateways. Furthermore, for added local redundancy, this apparatus utilizes peered border elements within an H.323 administrative domain.

Claims

1. Apparatus for a telephony gateway for routing a telephony call to or from a near-end telephony device, connected through a private branch exchange (PBX) to the gateway, and through either a public switched telephone network (PSTN) or a data network to a far-end telephony device situated at a far-end location, the apparatus comprising:

a processor;

a memory, connected to the processor and storing computer executable instructions therein; and

interface circuitry, controlled by and connected to the processor and also connected to the PBX and via corresponding network and telephony links to the data network and the PSTN, respectively, for selectively establishing a suitable communicative connection between the telephony device, through the PBX and the gateway, to either the PSTN or the data network;

wherein the processor, in response to performing the executable instructions;

(a) establishes a network connection over the data network to carry the telephony call from the near-end telephony device to the far-end telephony device;

(b) dynamically measures at least one predefined characteristic of a connection, over the data network and extending from the gateway to a peer gateway serving the far-end location, throughout a duration of the telephony call so as to define network measurements; and

(c) switches the telephony call from being carried over the data network to being carried over the PSTN if quality of service (QoS) of the network connection, as determined in response to said network measurements, decreases below a predefined threshold; and

(d) subsequently switches the telephony call back to being carried over the data network from the PSTN when the QoS increases above the predefined threshold.

2. The apparatus in claim 1 wherein the processor, in response to performing the executable instructions and to dynamic changes in QoS relative to the threshold, switches, the carriage of the telephony call back and forth between the data network and the PSTN such that the telephony call, throughout its duration, is always carried over an associated connection through the data network or the PSTN which then provides sufficient QoS.

3. The apparatus in claim 2 wherein said predefined characteristic comprises packet loss, latency or jitter.

4. The apparatus in claim 3 wherein the near-end and far-end telephony devices are each a telephone, a modem or a facsimile device.