Abstract: A technique for processing data carried by a Time Division Multiplexing (TDM) channel in a TDM network. A data stream associated with a TDM channel is monitored to determine if it contains data frames. If so, the channel associated with the data stream enters a clear channel mode which causes data in the data stream to be placed in packets for transfer over the packet network without being modified. Provided the data stream continues to carry data frames, the data stream stays in clear channel mode. After the data stream data no longer carries data frames, the channel exits clear channel mode.

Abstract: A technique for preserving information contained in a synchronization channel of a Time Division Multiplexing (TDM) frame across a packet network. Information contained in the synchronization channel of TDM frames is transferred over the packet network by a first gateway device that received the TDM frames. A second gateway device receives the synchronization channel information and places the information in one or more TDM frames. The TDM frames are transferred onto the TDM network.

Abstract: A communication device such as a Voice over Internet Protocol (VoIP) gateway multiplexes data intended for multiple voice connections within a single IP packet. If it is known in advance that packets for multiple connections between a given Originating Exchange (OEX) and Terminating Exchange (TEX) will travel between the Originating Gateway and Terminating Gateway, voice samples are multiplexed into the same VoIP packet. This “cell multiplexing” is accomplished by adding a cell header field to each cell payload portion. The cell header field indicates at least a connection identifier, so that the terminating gateway can route the payload to the correct TEX trunk. The scheme permits greatly improved efficiency in the carrying of VoIP traffic, especially where efficient voice coders are used.

Abstract: A communication device, such as a Voice over Internet Protocol (VoIP) gateway, determines a duration for Dual Tone Multi-Frequency (DTMF) tone portions of telephony signal. If the duration is less than a pre-determined amount, a minimum duration is enforced during DTMF playback at a remote end of a network connection connected to a destination gateway. Minimum playback duration can be enforced at the terminating gateway—however, the originatinggateway can also encode a DTMF packet with a minimum duration value. At the terminating receiver it is not always possible to playback exactly what happened at the originating point in the same time frame. One solution to is to, at the terminating gateway, drop the first portion of voice packets that overlap with the end portion of played back DTMF tones.

Abstract: A system that packetizes telephone calls using loss-less codecs for transmission over a communication link. The system includes a call admission control mechanism that admits calls for transmission over the communication link. An adaptive system which monitors bandwidth usage and which dynamically provides a feedback loop to the CAC system. The bandwidth allocation for transmission of the calls and the admission of calls is based upon actual bandwidth usage conditions in the system.