Dual speed hubs
In their early days, Fast Ethernet switches were relatively expensive . However, hubs suffered from the problem that as simple repeaters they could only support a single speed. Whilst normal PCs with expansion slots could be easily upgraded to Fast Ethernet with a new network card, computers with less common expansion mechanisms, or no expansion bus at all, and other equipment, such as printers, could be expensive or impossible to upgrade. Therefore, a compromise between a hub and a switch appeared known as a “dual speed hub”.
Such a device essentially consisted of two hubs (one of each speed) and a two port bridge between them. Devices were connected to the appropriate hub automatically based on their speed and the bridge handled inter-speed traffic. Since the bridge only had two ports and only one of those needed to be 100Mbps it could be much simpler and cheaper than a full fast ethernet switch. Such devices have been rendered obsolete by the decreasing cost of fast ethernet switches.