The half-duplex Ethernet system described in these Quick Reference Guides is obsolete. These Quick Reference Guides to Half-Duplex Ethernet are maintained here for historical reference only.
Modern Ethernet systems are based on full-duplex Ethernet segments linked together with Ethernet switches. Full-duplex Ethernet based on switches does not use the half-duplex colision detection system. Therefore, full-duplex Ethernet links do not depend on the maintenance of round trip signal timing and other guidelines described in these Quick Reference configuration guides.
The Quick Reference Guides to Half-Duplex Ethernet listed here describe the configuration guidelines for the original, and now obsolete, half-duplex Ethernet system that was in wide use until the full-duplex Ethernet standard was developed in the late 1990s.
These Quick Reference Guides to Half-Duplex Ethernet contain the official half-duplex mode configuration rules for 10 and 100 Mbps Ethernet systems based on repeater hubs. Half-duplex Ethernet is another name for the original Ethernet mode of operation which uses the CSMA/CD media access protocol. In a half-duplex system, multiple segments of Ethernet cables are linked together with repeater hubs, which serve to maintain the half-duplex signaling and timing specifications.
Included in these Quick Reference Guides to Half-Duplex Ethernet are the configuration rules for combining segments of half-duplex Ethernet with repeater hubs. This makes it possible to verify the configuration of any half-duplex mode Ethernet system, to make sure that it meets the official timing guidelines and that it will operate correctly.