either the 10 Mbit/s segment or the 100 Mbit/s segment, as appropriate. This obviated the need for an all-or-nothing migration to Fast Ethernet networks. These devices are considered hubs because the traffic between devices connected at the same speed is not switched. Fast Ethernet 100 Mbit/s hubs and repeaters come in two different classes: Class I delay the signal for a maximum of 140 bit times. This delay allows for translation/recoding between 100BASE-TX, 100BASE-FX and 100BASE-T4. Class II hubs delay the signal for a maximum of 92 bit times. This shorter delay allows the installation of two hubs in a single collision domain. Gigabit Ethernet Repeater hubs are defined in the standards for Gigabit Ethernet but commercial products have failed to appear due to the industry's transition to switching. Uses Historically, the main reason for purchasing hubs rather than switches was their price. By the early 2000s, there was little price difference between a hub and a low-end switch. Hubs can still be useful in special circumstances: For inserting a protocol analyzer into a network connection, a hub is an alternative to a network tap or port mirroring. A hub with both 10BASE-T ports and a 10BASE2 port can be used to connect a 10BASE2 segment to a modern Ethernet-over-twisted-pair network. A hub with both 10BASE-T ports and an AUI port can be used to connect a 10BASE5 segment to a modern network. As hubs have lower latency and jitter compared to switches – as long as there are no collisions –, they may be better suited for real-time networks, e.g. Ethernet Powerlink. See also Router (computing) USB hub References External links Hub Networking hardware