This paper describes the development of algorithm for direct data transmission between Raw VLBI Data Buffer (RVDB) and Huge Capacity Data Server (HCDS) operated in Korea-Japan Correlation Center (KJCC). The transmitted data is the VLBI observation data, which is recorded at each radio telescope site, and the data transmitting rate is varying from 1 Gbps, in usual case, upto 8 Gbps. The developed algorithm for data transmission enables the direct data transmission between RVDB and HCDS through 10 Gbps optical network using VLBI Data Interchange Format (VDIF). Proposed method adopts the conventional UDP/IP protocol, but in order to prevent the loss of data during data transmission, the packet error monitoring and data re-transmission functions are newly designed. The VDIF specification and VDIFCP (VDIF Control Protocol) are used for the direct data transmission between RVDB and HCDS. To validate the developed algorithm for data transmission, we conducted the data transmission from RVDB to HCDS, and compared to the transmitted data with the original data bit by bit. We confirmed that the transmitted data is identical to the original data without any loss and it has been recovered well even if there were some packet losses.