n.,obs. Before pervasive TCP/IP, this term was used of a machine that merely originated and read Usenet news or mail, and did not relay any third-party traffic. It was often uttered in a critical tone; when the ratio of leaf sites to backbone, rib, and other relay sites got too high, the network tended to develop bottlenecks. Compare backbone site
, rib site
. Now that traffic patterns depend more on the distribution of routers than of host machines this term has largely fallen out of use.