Nortel Networks Corporation

Genband US LLC

Dominic Walker

Graeme A Gibbs

Mark Stewart

In a communications network, voice and facsimile calls are established between first and second and second terminals via first and second media gateways in a communications network. Each gateway is capable of autonomous transitioning between a voice over IP (VoIP) call mode and a facsimile over IP (FoIP) call mode. A bearer path for the call is established via a media gateway controller. During call setup, the media gateways exchange confirmation of each gateway's capability to perform autonomous transitioning between VoIP and FoIP call modes. The call is established as a VoIP call, and, on a determination by the media gateways that a facsimile call is required, each media gateway autonomously transitions between its VoIP and FoIP call modes without the intervention of the media gateway controller.

Voice and fax over IP call establishment in a communications network

A packet-based network carries a stream of voice band data, such as PCM voice data, which can include tandem free operation (TFO) information. Voice data is usually subject to processing, such as compression, at an ingress entity. The ingress entity determines whether the stream of voice data contain tandem free operation (TFO) information and, if TFO information is present, sends the TFO information across the packet network without subjecting it to processing. This preserves the integrity of the TFO information. TFO information can be carried by an unprocessed channel having a bandwidth of less than 64 kbit/s. TFO information is reinserted at an egress entity of the packet network.

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Stevenage, United Kingdom

Dominic Walker