ARCnet Overview

Because it is a token-passing system, ARCnet is a deterministic network technology that is useful in situations in which a predictable throughput is required. Limitations of ARCnet include the fact that it operates at a rate of 2.5Mbps and can be used to create a LAN of up to only 255 computers. This might have once been an acceptable number of nodes for a factory floor setting, but in the large automated factories of today, this is a small number indeed. Although methods can be used to bridge ARCnet LANs together, other solutions can prove cheaper. Another benefit of upgrading from ARCnet to either Ethernet or Token-Ring is the increased management tools you'll have at your disposal to monitor and troubleshoot network performance and problems.

For a detailed discussion of how ARCnet works, including the network frame and message types used, see Chapter 13, "The Oldest LAN Protocol Is Still Kicking: ARCnet."