Abstract: Taught herein are a hub and an audio conference system. The system comprises a plurality of operator interface devices, each operator interface device being connected to an internet protocol (IP) network, and an audio mixing and routing hub. The hub is connected to each operator interface device through a duplex internet protocol audio channel over the IP network. In use, the hub is configured to receive at least a first primary audio stream from at least one of the operator interface devices, mix the primary audio streams to produce a first mixed audio stream, and transmit the first mixed audio stream to at least one of the operator interface devices.

Abstract: A bridge for linking a first communications network to a second communications network is taught. The bridge comprises a first bridge module linked to the first communications network and a second bridge module linked to the second communications network. The first bridge module is linked to the second bridge module by only an analog audio link and a General Purpose Input Output call negotiation signalling link such that generic digital data cannot effectively pass between the first communications network and the second communications network through the bridge elements. There is also provided a network terminal for connection to a network connected to the bridge and communications system comprising the bridge and first communications network.