Case Study: Pat Lee’s Home PC Network Chapter 1a Panko’s Business Data Networks and Telecommunications, 6th edition Copyright 2007 Prentice-Hall May only be used by adopters of the book

1a-2 Pat Lee’s Home Network Pat Lee is a vice president at FBP Wants a network in her home –Family’s main computer is the downstairs PC –Daughter Emily has a PC in her room –Wants to connect both to the Internet through a broadband (high-speed) cable modem service Perspective –A small LAN but has all the key network elements

1a-3 Figure 1a-1: Pat Lee’s Home Network 1. Coaxial Cable to ISP 2. Cable Modem 3. UTP Cord 4. Access Router

1a-4 Figure 1a-2: Coaxial Cable Two conductors are required for transmission

1a-5 Figure 1a-1: Pat Lee’s Home Network, Continued 5. UTP Cord 5. UTP Cord 6. B2-CD-13-5B-E4-65 PC in Study 6. A1-BD-33-6E-C7-BB PC in Emily’s Room 4. Access Router

1a-6 Figure 1a-5: Unshielded Twisted Pair (UTP) Cord With RJ-45 Connector 8-Pin RJ-45 Connector 4-Pair Unshielded Twisted Pair (UTP) Industry Standard Pen UTP Cord

1a-7 Figure 1a-1: Pat Lee’s Home Network, Continued 6. B2-CD-13-5B-E4-65 PC in Study 6. A1-BD-33-6E-C7-BB PC in Emily’s Room 7. File Sharing

1a-8 Figure 1a-1: Pat Lee’s Home Network, Continued 6. B2-CD-13-5B-E4-65 PC in Study 6. A1-BD-33-6E-C7-BB PC in Emily’s Room 8. Printer Sharing

1a-9 Figure 1a-3: Network Interface Cards (NICs) Internal NIC. Installed inside systems unit. Plugged into expansion slot on the mother board. PC Card NIC. Installed in PC Card slot in notebook and some PDAs.

1a-10 Internal NIC RJ-45 Jack PCI Connector Pins

1a-11 Figure 1a-6: UTP Cord RJ-45 Connector and Jack RJ-45 Jack On a Wall On a Switch or on a NIC RJ-45 Connector UTP Cord --- About as thick as a pencil --- Rugged and Flexible

1a-12 Computer Mother Board Mother Board PCI Slots for Expansion Boards (NICs, etc.) Slots for RAM Slot for Microprocessor (Pentium 4)

1a-13 Mother Board and Expansion Boards Connector Expansion Board (NIC) Expansion Slots Mother Board

1a-14 Figure 1a-4: Device Drivers

1a-15 Figure 1a-7: Home Network Access Router Switch Ports UTP Cords Run to Stations WAN Port UTP Cord Runs to Cable Modem About 4 inches (10 cm) Wide Power Jack for External Power

1a-16 Figure 1a-9: Ethernet Switch Operation Switching Table Port Host 10 A1-44-D5-1F-AA-4C 13 B2-CD-13-5B-E C3-2D-55-3B-A9-4F 16 D C4-B6-9F UTP Ethernet Switch A1-44-D5-1F-AA-4C B2-CD-13-5B-E4-65 D C4-B6-9F C3-2D-55-3B-A9-4F Frame To C3…

1a-17 Figure 1a-8: Logical Functions of the Access Router DHCP Server Function Router Function NAT Function Switch Function Access Router Cable Modem

1a-18 Figure 1a-10: Dynamic Host Configuration Protocol (DHCP) Access Router Cable Modem A1-BD-33-6E-C7-BB PC in Emily’s Room B2-CD-13-5B-E4-65 PC in Study ISP DHCP Server 1. IP Address = A DHCP Server provides User PCs with a temporary IP Address each time the user connects to the Internet The ISP only Gives each home a Single IP address

1a-19 Figure 1a-10: Dynamic Host Configuration Protocol (DHCP) Internal DHCP Server Access Router A1-BD-33-6E-C7-BB IP Address = PC in Emily’s Room B2-CD-13-5B-E4-65 IP Address = PC in Study ISP DHCP Server 1. IP Address = IP Address = IP Address = The access router’s internal DHCP server gives private IP Addresses to each PC

1a-20 Figure 1a-11: Network Address Translation (NAT) Access Router Cable Modem Webserver IP Address= Packet from Internal NAT Module PC in Study Packet from The access router’s NAT module translates between the private IP Addresses and the single ISP-given IP Address

1a-21 Figure 1a-11: Network Address Translation (NAT), Continued Access Router Cable Modem Webserver IP Address= Packet to Internal NAT Module PC in Study Packet to

1a-22 Perspective Pat Lee would like to serve the upstairs computer wirelessly This requires a wireless access point connected to the router or built into the router The upstairs computer must have a wireless NIC The downstairs computer, which is next to the access router, will still be connected via UTP If a separate wireless access point is used, it must be connected to the access router via UTP

1a-23 Figure 1a-12: Pat Lee’s Wireless LAN

1a-24 Figure 1a-12: Pat Lee’s Wireless LAN

1a-25 Figure 1a-13: Access Router with Wireless Access Point and Wireless NICs

1a-26 Configuration Each computer must be configured for communication with the outside world. See Chapter 1b for details. Each computer must be configured for file and print sharing. See Chapter 1b for details. The access router has a built-in webserver, allowing either of the two PCs to configure it using a browser. Not in the Book

1a-27 Figure 1a-14: Peer-to-Peer Service Versus Dedicated Servers Peer-to-Peer Networks –Clients serving other clients –Inexpensive—no need to purchase a dedicated server –Operational problems for other users if a user PC is turned off or crashes –Poor security: No password or shared password for shared directories

1a-28 Figure 1a-14: Peer-to-Peer Service Versus Dedicated Servers Dedicated Servers –Servers that are not also used simultaneously as user PCs –Do not use standard client versions of Microsoft Windows (XP, and so forth) –They use special server operating systems Known for historical reasons as network operating systems (NOSs) One popular NOS is Microsoft Windows (latest version is Windows Server 2003) Another is Unix, which has versions for PCs (Linux, BSD, etc.)

1a-29 Figure 1a-14: Peer-to-Peer Service Versus Dedicated Servers Dedicated Servers –NOSs for dedicated servers are rich in functionality They are designed to serve many users with many services Have strong security –Unfortunately, dedicated servers are very expensive –Installation requires specialized training –Make no sense for home use

1a-30 Figure 1a-14: Peer-to-Peer Service Versus Dedicated Servers Network Attached Storage (NAS) Units –Boxes that cost $200 to $500 –Contain a large shared hard drive –RJ-45 plugs allow the NAS to be connected to the switch in the access router via UTP –No mouse or keyboard; has a built-in webserver that can be managed remotely by a client PC –Do not lose availability when a user PC is turned off or crashes –Better security than PC file service –Backup is crucial