<P> A network switch (also called switching hub, bridging hub, officially MAC bridge) is a computer networking device that connects devices together on a computer network by using packet switching to receive, process, and forward data to the destination device . </P> <P> A network switch is a multiport network bridge that uses hardware addresses to process and forward data at the data link layer (layer 2) of the OSI model . Some switches can also process data at the network layer (layer 3) by additionally incorporating routing functionality . Such switches are commonly known as layer - 3 switches or multilayer switches . </P> <P> Switches for Ethernet are the most common form of network switch . The first Ethernet switch was introduced by Kalpana in 1990 . Switches also exist for other types of networks including Fibre Channel, Asynchronous Transfer Mode, and InfiniBand . </P>

What is a switch that works at more than one layer of the osi model called