The Role of ESLEA in the development of eVLBI

The internet has been used for data transfer in radio astronomy ever since its inception; however it is only recently that network bandwidth capability means that the internet becomes competitive with traditional forms of data storage. Very Long Baseline Interferometry (VLBI) uses widely separated telescopes between which high bandwidth direct connections have not been feasible until recently. The academic networks now allow us to connect at high data rates (~1Gbps) in "eVLBI". The ESLEA project (Exploitation of Switched Lightpaths for E-science Applications) has played a major role in the development of eVLBI. We outline this development in this paper.