A conference system comprising: a control unit (1, CU); and a plurality of discussion units (2, DU), connected by a ring connection or a daisy chain connection to the control unit, wherein the control unit is configured to repeatedly transmit and receive a running packet to and from the plurality of discussion units, each discussion unit of the plurality of discussion units comprising: a DU control portion, and a DU communication portion, the control unit comprises: a CU control portion comprising a plurality of audio slots, each audio slot being configured for receiving audio information from a discussion unit of the plurality of discussion units, wherein the number of audio slots corresponds to the number of discussion units that may be enabled for speech at the same time, and a CU communication portion; wherein the DU control portion is configured to add a request flag, corresponding to a speech request, to the running packet, the DU communication portion is configured to transmit the running packet, with the request flag added, to the control unit, when the running packet, with the request flag added, is received at the control unit, the CU communication portion is configured to transmit a content acquisition packet, carrying an acquisition command to acquire a content, to the discussion unit which added the request flag, if an audio slot of the plurality of audio slots is vacant, and after the content acquisition packet is transmitted, the CU control portion is configured to assign the audio slot of the plurality of audio slots to the discussion unit which added the request flag. a control unit (1, CU); and a plurality of discussion units (2, DU), connected by a ring connection or a daisy chain connection to the control unit, wherein the control unit is configured to repeatedly transmit and receive a running packet to and from the plurality of discussion units, each discussion unit of the plurality of discussion units comprising: a DU control portion, and a DU communication portion, a DU control portion, and a DU communication portion, the control unit comprises: a CU control portion comprising a plurality of audio slots, each audio slot being configured for receiving audio information from a discussion unit of the plurality of discussion units, wherein the number of audio slots corresponds to the number of discussion units that may be enabled for speech at the same time, and a CU communication portion; a CU control portion comprising a plurality of audio slots, each audio slot being configured for receiving audio information from a discussion unit of the plurality of discussion units, wherein the number of audio slots corresponds to the number of discussion units that may be enabled for speech at the same time, and a CU communication portion; wherein the DU control portion is configured to add a request flag, corresponding to a speech request, to the running packet, the DU communication portion is configured to transmit the running packet, with the request flag added, to the control unit, when the running packet, with the request flag added, is received at the control unit, the CU communication portion is configured to transmit a content acquisition packet, carrying an acquisition command to acquire a content, to the discussion unit which added the request flag, if an audio slot of the plurality of audio slots is vacant, and after the content acquisition packet is transmitted, the CU control portion is configured to assign the audio slot of the plurality of audio slots to the discussion unit which added the request flag.