ions to the traffic. They read the source address in each frame and build up an address table containing all stations that have transmitted a frame as shown in Figure 6.33. If the location is not yet known, frames are transmitted to all ports. The address table is updated continuously to allow a workstation to move from one port to another. In the network topology shown in Figure 6.31, we can change the repeater to a switch that is actually a fast multiport bridge. Now the frames from one computer to another are transmitted only from the source port to the destination port, and two other computers connected to different ports of the switch may transmit to each other at the same time. To allow this, the internal capacity of a switch must be much higher than the data rate at one port. Connections in 10BaseT use two pairs, one for reception and the other for transmission, and switches also allow full-duplex transmission between a workstation and the switch. Then, for example, two computers can transmit and receive simultaneously to each other and the maximum transmission capacity is increased from 10 to 20 Mbps. Note that collisions never occur in sections connected to ports 2 and 3 in Figure 6.33 because there is only one transmitter connected to each pair and the switch transmits only error-free frames further. Switching table is updated Data link layer address table if the source address in a received frame is unknown or MAC address: binded to a different port. 080020000001 If no frames from the host 080020000002 are received for a certain period of time, its address is 080020000003 cleared from the table. 080020000008 080020000007 MAC address: 080020000001 Switch 080020000002 080020000007 080020000003 080020000008 Figure 6.33 Address or switching table of an autolearning switch. Introduction to Telecommunications Network Engineering 6.5.8 Fast Ethernet The fast Ethernet standard is 100BaseT and carries data frames at 100 Mbps. This results in the reduction by a factor of 10 in the bit time, which is the amount o