The NTTFAX-D4300 was released as a heat-sensitive digital G4 facsimile machine. To support the INS Net64, this model provides high-speed transmission of a copy of an A4-sized standard sheet in three seconds and a high resolution of up to 400 x 400 ppi. It can register up to 200 numbers for abbreviated dialing and use two megabytes of ample memory for providing various transmission and reception functions. In addition, the NTTFAX-D4300 enables both facsimile and telephone communications simultaneously using two information channels (B channels) for the ISDN network.