Brown Brown/White Orange Blue/White Blue Orange/White Green Green/White 1 2 3 4 5 6 7 8 EIA/TIA 568A in Software

Generator UPC-A Supplement 5 in Software Brown Brown/White Orange Blue/White Blue Orange/White Green Green/White 1 2 3 4 5 6 7 8 EIA/TIA 568A

Brown Brown/White Green Blue/White Blue Green/White Orange Orange/White 1 2 3 4 5 6 7 8 EIA/TIA 568B

EXAM TIP For the CompTIA Network+ exam, you won t be tested on the TIA/EIA 568A or B color codes Just know that they are industry-standard color codes for UTP cabling

Like any other Ethernet cabling system, 10BaseT has limitations, both on cable distance and on the number of computers The key distance limitation for 10BaseT is the distance between the hub and the computer The twisted-pair cable connecting a computer to the hub may not exceed 100 meters in length A 10BaseT hub can connect no more than 1024 computers, although that limitation rarely comes into play It makes no sense for vendors to build hubs that large or more to the point, that expensive because excessive collisions can easily bog down Ethernet performance with far fewer than 1024 computers

10 Mbps Baseband No more than 1024 nodes per hub Star-bus topology: physical star, logical bus Uses CAT 3 or better UTP cabling with RJ-45 connectors 100 meters between the hub and the node

Just a few years after the introduction of 10BaseT, a fiber-optic version appeared, called 10BaseFL As you know from the previous chapter, fiber-optic cabling transmits data packets using pulses of light instead of using electrical current Using light instead of electricity addresses the three key weaknesses of copper cabling First, optical signals can travel much farther The maximum length for a 10BaseFL cable is up to two kilometers, depending how it is configured Second, fiber-optic cable is immune to electrical interference, making it an ideal choice for high-interference environments Third, the cable is much more difficult to tap into, making it a good choice for environments with security concerns 10BaseFL uses multimode fiber-optic and employs either an SC or an ST connector NOTE 10BaseFL is often just called 10BaseF

Figure 4-13 shows a typical 10BaseFL card Note that it uses two fiber connectors one to send and one to receive All fiber-optic networks use at least two fiber-optic cables While 10BaseFL enjoyed some popularity for a number of years, most networks today are using the same fiber-optic cabling to run far faster network technologies

10 Mbps Baseband No more than 1024 nodes per hub Star-bus topology: physical star, logical bus Uses multimode fiber-optic cabling with ST or SC connectors 2000 meters between the hub and the node

So far you ve seen two different flavors of Ethernet: 10BaseT and 10BaseFL Even though these use different cabling and hubs, the actual packets are still Ethernet packets As a result, it s common to interconnect different flavors of Ethernet Since 10BaseT and 10BaseFL use different types of cable, you can use a media converter (Figure 4-14) to interconnect different Ethernet types

Figure 4-14 Typical copper-to-fiber Ethernet media converter (photo courtesy of TRENDnet)

Once you have an Ethernet network in place, you can extend or enhance that network in several ways You can install additional hubs to connect multiple local area networks, for example A network bridge can connect two Ethernet segments, effectively doubling the size of a collision domain You can also replace the hubs with better devices to reduce collisions

Sometimes, one hub is just not enough Once an organization uses every port on its existing hub, adding additional nodes requires additional hubs or a device called a bridge Even fault tolerance can motivate an organization to add more hubs If every node on the network connects to the same hub, that hub becomes a single point of failure if it fails, everybody drops off the network There are two ways to connect hubs: an uplink port or a crossover cable You can also connect Ethernet segments using a bridge