1. 1 Chapter Overview  Network Cables  Network Interface Adapters  Network Hubs

2. 2 Cable Topologies  Bus  Star  Ring  Hierarchical star  Mesh  Wireless

3. 3 Bus Topology

4. 4 Star Topology

5. 5 Ring Topology

6. 6 Ring Network Types  Physical ring  Logical ring  Double ring

7. 7 Hierarchical Star Topology

8. 8 Mesh LAN Topology

9. 9 Mesh Internetwork

10. 10 Hybrid topology

11. 11 Twisted-Pair Cable

12. 12 Fiber Optic Cable

13. 13 Fiber Optic Connectors

14. 14 Network Interface Adapters  Called network interface cards (NICs) when installed in expansion slots  Provide the computer with an interface to the network  Usually take the form of an expansion card  Can be integrated into the motherboard

15. 15 Network Interface Adapter Functions  Data-link protocol implementation  Data encapsulation  Signal encoding and decoding  Data transmission and reception  Data buffering  Serial/parallel conversion  Media Access Control (MAC)

16. 16 NIC Purchasing Checklist  Does the NIC use the correct data-link layer protocol?  Does the NIC use the correct bus type?  Does the NIC have the correct cable connector?

17. 17 Installing a NIC  To install a NIC into a standard expansion slot on a desktop computer: 1. Power off the computer. 2. Open the computer case. 3. Locate a free slot. 4. Remove the slot cover. 5. Insert the card into the slot. 6. Secure the card in the slot. 7. Close the computer case.

18. 18 Network Interface Adapter Requirements  Network interface adapters use the following hardware resources:  Network interface adapters use the following hardware resources: An interrupt request (IRQ) An interrupt request (IRQ) An input/output (I/O) port address An input/output (I/O) port address A memory address A memory address A direct memory access (DMA) channel A direct memory access (DMA) channel  Most network interface adapters require only an IRQ and an I/0 port address.

19. 19 Troubleshooting Network Interface Adapters  Network interface adapters rarely malfunction.  Test all other networking components first.  Use the network interface adapter manufacturer’s diagnostics.  Replace network interface adapters rather than trying to repair them.

20. 20 Understanding Ethernet Hubs  A hub connects all of the computers on a star or ring network.  Ethernet hubs are available in various sizes.  A hub creates a shared network medium on a LAN.

21. 21 Connecting Ethernet Hubs  Most hubs have an uplink port.  Uplink ports provide a straight-through circuit.  To connect two hubs, plug a cable into the uplink port on one hub and into a standard port on the other hub.

22. 22 Understanding MAUs

23. 23 Chapter Summary  The network topology is the pattern used to connect computers and other devices with the cable or other network medium.  The three primary LAN topologies are bus, star, and ring.  Unshielded twisted-pair (UTP) cable in the star topology is the most common network medium used today.  A network interface adapter provides the interface that enables a computer to connect to a network.  The network interface adapter and its driver implement the data-link layer protocol on the computer.Hubs are devices that connect computers on a star or ring network.