The 5-4-3 Rule in Thicknet
One thicknet Ethernet network can have a maximum of five backbone segments connected using repeaters (based on the IEEE 802.3 specification), of which up to three can accommodate computers. The length of the transceiver cables is not used to measure the distance supported on the thicknet cable; only the end-to-end length of the thicknet cable segment itself is used.
Between connections, the minimum thicknet cable segment is 2.5 metres (about 8 feet). This measurement excludes transceiver cables. Thicknet was designed to support a backbone for a large department or an entire building.