DONJIN digital trunk voice boards adopt the lastes DSP, single board can provide 1E1/2E1/4E1 digital trunk interface, 30/60/120 channels voice processing ability and 1/2/4 signaling(MTP, TUP, ISUP, SCCP) links processing ability. Strong DSP technology can effectively reduce the host load. Hardware can be updated through network to guarantee high-impedance, high-capacity application system operating effectively and stably, so it can be easy to construct multi-functional, cost-effective and updatable applic ation system to protect user investment. The interface of these boards can be BNC or RJ48.