Today a new standard, the Gigabyte System Network (GSN), is emerging for computer networking using fast, full-duplex connections with an effective bandwidth of 800 MByte/s in each direction. This paper describes GSN, including the switch structure and its very low latency protocol called Scheduled Transfer (ST). An overview of available components will be given, together with some examples of how this standard can be applied in high end computing and in future high-energy physics data acquisition systems