What do you mean by switches ?Ripunjay Tiwari
Ans. A switch is a device that provides bridging functionality with greater efficiency. A switch may act as a multiport bridge to connect devices or segments in a LAN. The switch has a buffer for each link (network) to which it is connected. When it receives a packet, it stores the packet in the buffer of the receiving link and checks the address (and some time CRC) to find the outgoing link. If the outgoing link is free (no change of collision), the switch sends the frame to the particular link.
Switches are made based on two different strategies (called fabrics ) – store-and-forward and cut-through. A store-and-forward switch stores the frame in the input buffer until the whole packet has arrived. A cut-through switch, on the other hand, forwards the packet to the output buffer as soon as the destination address is received. Fig. 5.17 shows the concept of a switch.
In this figure, a frame arrives at port 2 and is stored in the buffer. The CPU and the control until, using the information in the frame, consult the switching table to find the output port. The frame is then sent to port 5 for transmission.