rdware is necessary to mix 100Base-TX and 100Base-T4 hubs in the same stack. Some 100Base-T4 hubs will even integrate both 100Base-TX and 100Base-T4 ports to accommodate both technologies. Fast Ethernet adapters, better known as 10/100 adapters, are designed with both 10- Mbps and 100-Mbps chips inside. A majority of Fast Ethernet adapters includes drivers and provides a single port with the capability to switch automatically between 10 Mbps and 100 Mbps without any modification on the client side. The availability of 10/100 adapters make it possible to buy incrementally and upgrade the LANs at some future date by merely replacing the hub or switch with one that supports 100Base-T. With pricing comparable to 10-Mbps adapters, buying Fast Ethernet adapters makes a great deal of sense. With their double speed capability and competitive pricing, Fast Ethernet adapters are a no-brainer purchase for your network. The trick is to buy the right adapter. Look for one that provides a single port for automatic switching and make sure that it does not rely too heavily on the CPU. When it comes time to switch to Fast Ethernet, having this groundwork in place will make the transition easier. The fiber- based 100Base-FX systems are not vulnerable to radio frequency interference and can extend connections out to over a mile of cable. FAST Ethernet and Gigabit Ethernet are the clear winners in high-bandwidth LAN infrastructure. GIGABIT ETHERNET A backbone's bandwidth must be greater than that of the nodes that connect to it, and greater even than the aggregate of all links that feed into it. Therefore, as 100 Mbps Ethernet extends to the desktop, faster standards such as Gigabit (1000 Mbps) Ethernet will become increasingly common on backbones. One need only consider the plummeting cost of 100 Mbps Ethernet network interface cards (NIC) to understand just how fast this migration is occurring. Gigabit Ethernet (also known as 802.3z) was initially developed by the Gigabit Ethernet Alliance (GEA), which consisted of about 50 vendor