[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}. Now that traffic patterns depend more on the
distribution of routers than of host machines this term has largely
fallen out of use.
[glossary]
[Reference(s) to this entry by made by: {backbone site}]