Introduction
To start off, ARCnet is not a standardized network. All information provided here is gathered through the years by different people and by just making mistakes, so if you have other experiences don't be surprised, but share them with us. This way we can all learn from it.
ARCnet (Attached Resource Computer NETwork) was originally developed by Datapoint Corporation in 1968, way before OSI and the like. The original purpose was a harddisk interface, later it became popular as a local area network.
According to the Datapoints ARCNET Designer's Handbook 61610 © 1988, ARCnet is: a high-performance, bus-structured, token-passing, base-band network linking two or more computers through high-speed connections. The network can support up to 255 nodes, transmitting data at a rate of 2.5 Mbps up to 4 miles in distance (when active hubs are used between nodes).
ARCnet uses a Token Passing bus structure much like IEEE802.4. It's most common speed is still 2.5 Mbps, but we know of versions runnig 20 Mbps (ARCnet plus by SMC, NCR and Datapoint) and the rumour is there is even a 100 Mbps (by Thomas Conrad) version. So it seems like it is still in progress. The reason for this is probably its easyness (ARCnet is very tolerable) in cabling and the predictable delivery of packets through the use of a token architecture.
ARCnet (Attached Resource Computer NETwork) was originally developed by Datapoint Corporation in 1968, way before OSI and the like. The original purpose was a harddisk interface, later it became popular as a local area network.
According to the Datapoints ARCNET Designer's Handbook 61610 © 1988, ARCnet is: a high-performance, bus-structured, token-passing, base-band network linking two or more computers through high-speed connections. The network can support up to 255 nodes, transmitting data at a rate of 2.5 Mbps up to 4 miles in distance (when active hubs are used between nodes).
ARCnet uses a Token Passing bus structure much like IEEE802.4. It's most common speed is still 2.5 Mbps, but we know of versions runnig 20 Mbps (ARCnet plus by SMC, NCR and Datapoint) and the rumour is there is even a 100 Mbps (by Thomas Conrad) version. So it seems like it is still in progress. The reason for this is probably its easyness (ARCnet is very tolerable) in cabling and the predictable delivery of packets through the use of a token architecture.
The ARCnet devices
ARCnet knows 5 different types of devices:
Active hub
They split and amplify the signal. The are a bit like the hubs in Ethernet. Unused ports on an Active Hub do not need termination, although it is advised to terminate them. The active hubs provide electrical isolation at each port. They feature problem detection and segment partitioning, so only the segment on that port will be affected by problems of one of the attached devices to that segment.
Active Link
Which actually is a repeater. It has two ports and acts as a two port active hub.
Passive hub
They just split the signal, which means if it is a four port hub, every port gets 1/3 of the signal (one port was incoming). Unused ports on an Passive Hub do need termination. A Passive Hub is a small box with 4 BNC connectors and an internal resistor network.
Bus NIC (RIM)
A network card with a high-impedance driver (SMC 9068), only suitable for bus-segments.
Star NIC (RIM)
A network card with a low-impedance driver (SMC 9058), only suitable for a star-segments.
Active hub
They split and amplify the signal. The are a bit like the hubs in Ethernet. Unused ports on an Active Hub do not need termination, although it is advised to terminate them. The active hubs provide electrical isolation at each port. They feature problem detection and segment partitioning, so only the segment on that port will be affected by problems of one of the attached devices to that segment.
Active Link
Which actually is a repeater. It has two ports and acts as a two port active hub.
Passive hub
They just split the signal, which means if it is a four port hub, every port gets 1/3 of the signal (one port was incoming). Unused ports on an Passive Hub do need termination. A Passive Hub is a small box with 4 BNC connectors and an internal resistor network.
Bus NIC (RIM)
A network card with a high-impedance driver (SMC 9068), only suitable for bus-segments.
Star NIC (RIM)
A network card with a low-impedance driver (SMC 9058), only suitable for a star-segments.