The main problem of conferences realization on PBX is the cost of equipment, which is so great because of high technical requirements to the reliability and functionality of the hardware component. Using the advanced know-how of processors manufacturing, the Dialogic corporation managed to create equipment appropriate to the highest requirements on reliability and functional possibilities at a rather low cost.

A conferencing board of DCB series contains one or more (maximum three) DSP-processors, each of which has 32 conference resources, and each such a conference resource may be used by a single or several conferees. In an arbitrary conference no more than 32 conference resources can be used so that only the number of available DSP-processors on the installed conferencing boards limits the whole number of conferences that can be carried out simultaneously. The conferencing boards are connected to each other and to the boards of the digital telephone interface through a special SCbus. Finally, the digital telephone interface boards can be connected to a PBX using practically any of ISDN PRI protocols (for example: DSS1 (ETSI-Euro ISDN), Q-SIG, VN3 (French National ISDN), 1TR6 (German National ISDN) etc.) as the Network Terminal or Terminal Equipment. All this hardware is installed in free ISA- and/or PCI-slots (depending on a board modification) of a standard PC or industrial computer for large-size systems.