Difference Between Fast Ethernet and Gigabit Ethernet

Fast Ethernet and Gigabit Ethernet provide faster Ethernet options.Both have gained widespread acceptance in networks today,with fast Ethernet most likely being used between networking devices or to servers.Fast Ethernet retains many familiar features of 10-Mbps Ethernet variants.The age  old CSMA/CD logic stil exists,but it can be disabled for full-duplex point to point topologies in which no collisions can occur.A varient of cabling options is allowed-unshielded and shielded copper cabling as well as multimode and single mode fiber.Both Fast Ethernet shared hubs and switches can be deployed.However,because Fast Ethernet gained market acceptance around the same time that LAN switching became popular,most Fast Ethernet cards either are connected to a switch or are directly cabled to another device.

       The two key additional features of Fast Ethernet,as compared to 10-Mbps Ethernet,are higher bandwidth and auto negotiation.Fast Ethernet operates at 100 Mbps enough said.The other key difference,auto negotiation,allows an Ethernet card or switch to operate at 10 or 100 Mbps. Also,support for half-duplex or full-duplex operation is negotiated.If the other device,such as a 10 BaseT NIC,does not support auto negotiation,auto negotiation settles for half-duplex operation at 10 Mbps.The auto negotiation process has been know to fail.
    Cisco recommends that,for devices that seldom move you should configure the LAN switch and the device to use identical desired rather than depend on auto negotiation.Generally,for ports that used for end-user devices,auto negotiation is enabled because these devices are moved frequently relative to servers or other network devices,such as routers,Gigabit Ethernet also retains many familiar features of slower Ethernet variants. CSMA/CD is still used and can be disabled for full-duplex support.Although gigabit hubs are allowed,it is more likely that Gigabit Ethernet  switch ports will be the most popular use for Gigabit Ethernet,along with use as a trunk between high-throughput switches and routers.
   Gigabit Ethernet is similar ti its slower cousins in several ways.The most important similarity is that the same Ethernet headers and trailers are used,no matter whether it;s 10 Mbps,100 Mbps or 1000 Mbps.If you understand how Ethernet works for 10 and 100 Mbps,then you know most of what you need to know about Gigabit Ethernet. Gigabit Ethernet differs from the slow specifications in how it encodes the signals onto the cables.Gigabit Ethernet is obviously faster,at 1000 Mbps or 1 Gbps.
    

        Both Fast Ethernet(FE) and Gigabit Ethernet(GE) relieve congestion in some fairly obvious ways.Collisions and wait time are decreased when compares to 10-Mbps Ethernet simply because it takes 90 percent(FE) or 99 percent(GE) less time to transmit the same frame on the faster LANs. Capacity is greatly increased as well:If all frames were 1250 bytes long,a theoretical maximum 0f 10,000 frames per second could be reached of Fast Ethernet,and a theoretical maximum of 100,000 frames per second could be reached on Gigabit Ethernet.