10Base5 is an IEEE specification for cable with a speed of 10 Mbps, a signalling type of baseband and a 500 metre segment length. It is also known as standard Ethernet.
This topology makes use of a much thicker coaxial cable, known as thicknet. Thicknet uses a bus topology and can support as many as 100 nodes (stations, repeaters, etc) to each backbone segment. The backbone, or trunk segment, is the main cable from which transceiver cables are connected to stations and repeaters. The distances and tolerances for thicknet are greater than those for thinnet: a thicknet segment can be 500 metres (1640 feet) long for a total network length of 2500 metres (8200 feet).