VLBI data transfer over fast long-distance hybrid network

VLBI (Very Long Baseline Interferometry), which combine many telescopes by the technical of interferometry, can achieve the effect of a large telescope observations. With the development of high-speed network, telescopes achieve real-time observation by network connection, which is called e-VLBI. In this paper, the network connectivity of radio telescope in China and Europe for e-VLBI is briefly described. Then, end to end network performance measurement experiment for e-VLBI over CSTNET is finished to describe how VLBI data translates over fast long-distance network. TCP and UDP protocols are compared for e-VLBI transfer performance. Several factors of affecting the performance of e-VLBI experiment are discussed. Finally, using cloud computing, VDCF (e-VLBI distributed cloud computing framework) is established.