Abstract: The invention relates to methods and apparatus for switching a call from an unreliable network to an alternate network when a QoS of the network falls below a predetermined threshold. The invention includes a telephone call switching apparatus which monitors the QoS of the call. When the QoS of the call falls below a first threshold the switching apparatus establishes a connection over an alternate network. If after a predetermined time period or after the QoS falls below another predetermined threshold the call is transferred to the alternate network connection. While the switching apparatus is maintaining multiple network connections, the idle network connection remains muted.

Abstract: The invention is a novel method of processing incoming and outgoing call requests by a switching unit such as a KSU, PBX or PC server. Each established circuit and each call request is associated with a priority. For an outgoing call request, if an available external bandwidth channel of the appropriate type is found, then a circuit is established at once. However, if there is no available external bandwidth channel of the appropriate type, then the priority of the outgoing call request is checked against the priority of the established circuits. If a lower-priority circuit is found, then that circuit is torn down and a new circuit is established between the internal bandwidth channel carrying the outgoing call request and the external bandwidth channel formerly occupying the established circuit that was torn down. In the case of an incoming call request, a destination terminal device and associated internal bandwidth channels will be specified and availability thereof is verified.

Abstract: The invention relates to methods and apparatus for determining whether a CPS should employ a standard interface or an unreliable network for routing telephone calls. The invention includes a telephone call switching apparatus which includes a routing engine configured to receive a telephone call from a terminal connected to the call switching apparatus and a switching matrix connected thereto. The telephone call includes a destination code. The routing engine is configured to receive the telephone call from a terminal or trunk line, determine an unreliable network route for the telephone call based upon the destination code, and provide a message to a call manager associated with the unreliable network route (via the switching matrix). The message includes the destination code. The routing engine is also configured to receive a response from the call manager; and route the call over the unreliable route if the response is affirmative.

Abstract: A call progress signal monitor includes a translation circuit for generating data signals indicative of predetermined signal characteristics in a TDM PCM signal channel. A processor implemented detection circuit is responsive to the data signals for detecting call progress tones and silence. The translation circuit includes a translation ROM for assigning PCM signal samples with code values in a range with maximum and minimum limits. A comparator generates a comparison value signal in response to the code values of an instant sample and an immediately previous sample. An encoding ROM generates a trend data byte in response to an instant comparison value signal and a plurality of consecutive previous comparison value signals. The instant code value and the instant trend data byte comprise data signals for identification of the progress tones and silence occurrences by the detection circuit.