2.2 Select the appropriate topology for various token-ring and Ethernet networks.

Generally, there are four network topologies: star, bus, ring and mesh. Most people are only familiar with the first three topologies and may fail the FTQ 2.2.1 on the first try. However, don’t worry, since you know the answer for FTQ 2.2.1 now, you should answer this type of question correctly in the future.

Star topology

Bus topology

Ring

Figure 2.1 Three major network topologies

In the star topology, you will find all the cables are wired to the Hub or the switch. Almost all the hub has LEDs to indicate the port status, which can let you easily determine where the problem is located. If there is a problem with one machine, it will effect only one port. It will not affect the whole network.

Imagine in a ThinNet with bus topology, if one of the T connector is broken, it may affect the whole network. Please make sure that this does not mean when one machine shutdown, the whole network doesn’t work. Look at the following figure of T-connector:

Figure 2.2 BNC T-connector

 

You connect the networking cable to port A and B, port C is connected to the NIC on the NIC on the PC directly. Therefore, if you shutdown the PC, you can still pass the signals from A to B, it will not affect the other machines on the network. However, if there are some broken in between A and B, the whole network will be down. To test the cable connectivity, you can use the cable tester. But generally you don’t have this kind of device on hand. So many people just separate the network and terminate the network with terminator in middle to see if that segment works fine.

Sometimes people will see the term barrel connector. In fact, barrel connector looks like a T-connector while doesn’t have port C, which means that you can not connect it to the Network card. Barrel connector only connects two cables together, somewhat like a repeater, but not regenerate the signal.

In the bus topology network, such as ThinNet, one bus can have only two terminators. If you see the diagram such as in FTQ 4.2.11 that has three terminators, you need to reorganize the network to only have two terminators. In addition, one bus can only have one point grounded. If you see that a bus network has been grounded two places, it is wrong.

10BaseT, 100Base T and ATM are typical star topology networks.

ThinNet and thicknet are typical bus topology networks.

Token ring and FDDI are the typical network of ring topology. FDDI provides dual counter-rotating rings. The second ring serves as backup in the event the primary ring fails. In such a case, the second ring carries the network traffic. FDDI will not fail when one ring is down.

FDDI is the only network with build-in backup. Other types of networks such as 10BaseT, ThinNet don’t provide backup.

Therefore, if Microsoft asks you to consider a network build a network with connectivity backup which doesn't any other implementation and is using 10BaseT or ThinNet, the proposed solution does not produce the required result. J

In the real world, you don’t see much mesh network very often. The Internet is of mesh topology. Because mesh topology provides multiple paths, routers are used to build the mesh network. Please note that a bridge can only support spanning tree topology, which cannot provide the multiple paths from the source to the destination.

Exam Tip: If Microsoft asks you to provide the devices support multiple paths, the only correct choice is a ROUTER.

Q: In your former tutorial, you write 'Microsoft thought the network using star topology is cheaper than Bus, so we have to choose A for FTQ 2.2.2 even I have dispute on that.' Why now you provide B as the correct answer?

A: Microsoft has made the correction on the new adaptive exam.