The Basics of Network Switching Technology

Industrial networks increasingly incorporate switching gear to avoid bottlenecks that can bog down critical operations. Networks are starting to become a critical part of many industrial installations. Production equipment increasingly incorporates diagnostics that are available over an Ethernet, and ever more factory gear is not only networked but also has its own IP address. No wonder, then, that the networks to which these devices connect is becoming more complicated. Industrial networks are increasingly likely to make use of Ethernet switches, hubs, and other connective equipment to better manage network traffic so there are no delays in timecritical data. Modern networks can potentially use numerous styles of switching equipment. But there are important differences among these devices. Circumstances dictate where one type makes more sense than another. A brief tutorial can explain how to tell whether a network will benefit from a specific kind of switching device, and how to add switches so the network performs better than before. The latter point is important because switches can both harm and benefit network capacity and speed. They are not a cure-all for network issues. The uninitiated may have a mental image of a network "switch" as something containing electrical contacts like an electromechanical relay. This image is nothing at all like reality. To begin with, network switches are entirely solid-state devices. And the switching action they provide is more sophisticated than simple switching, as in on/off switches. Network switches examine each data packet and process it accordingly. In this regard, they are more able than another type of network connection called a hub. A hub simply repeats the signal it sees on one port to all the others that contain connections. All nodes connected to a hub see the same traffic. There is no intelligence behind either the data transmission or the determination