1. © 2007-2010 Cisco Systems, Inc. All rights reserved. Cisco Public ITE PC v4.1 Chapter5 1 Computer Networks

2. ITE PC v4.1 Chapter 5 2 © 2007-2010 Cisco Systems, Inc. All rights reserved. Cisco Public Decimal to Binary Try: To binary 130 2780 678,123 53,992 To decimal 100101 11100100 100010 110110

3. ITE PC v4.1 Chapter 5 3 © 2007-2010 Cisco Systems, Inc. All rights reserved. Cisco Public Computer Networks Network Devices are Linked Using a Variety of Methods Copper Cabling Uses electrical signals to transmit data between devices Fiber-optic Cabling Uses glass or plastic wire, also called fiber, to carry information as light pulses Wireless Connections Uses radio signals, infrared technology, or satellite transmissions

4. ITE PC v4.1 Chapter 5 4 © 2007-2010 Cisco Systems, Inc. All rights reserved. Cisco Public Computer Networks Copper Cabling Unshielded Twisted Pair (UTP) Used for telephone communications and most Ethernet networks Twisted to protect against crosstalk Noise generated by adjacent pairs of wires Shielded Twisted Pair (STP) Same as twisted pair BUT has metal foil around the wires to prevent Electromagnetic Interference

5. ITE PC v4.1 Chapter 5 5 © 2007-2010 Cisco Systems, Inc. All rights reserved. Cisco Public Computer Networks Cat5, Cat5e, Cat6 Pros Cheap Common Easy to setup Cons Maximum length -100m Cat5 Maximum speed – 100 Mbps Cat5e – 1000 Mbps (Gigabit Ethernet) Cat6 – 10 Gbps Electromagnetic Interference

6. ITE PC v4.1 Chapter 5 6 © 2007-2010 Cisco Systems, Inc. All rights reserved. Cisco Public Computer Networks Cat5 Straight-Through Wires connected the same at both ends Connect 2 different types of equipment Crossover Wires have opposite pin configurations Connect 2 same type of equipment

7. ITE PC v4.1 Chapter 5 7 © 2007-2010 Cisco Systems, Inc. All rights reserved. Cisco Public Computer Networks Fiber-Optic Cabling Light travels through glass core with a surrounding protection Advantages No electromagnetic interference (no electricity) Max Length – ~10km Max Speed – 100 Gbps Water does not interefere Disadvantage Cost! Fragile

8. ITE PC v4.1 Chapter 5 8 © 2007-2010 Cisco Systems, Inc. All rights reserved. Cisco Public Computer Networks Wireless Networks Wireless Router Plugged Into Modem Wireless Network Interface Card in PC Advantages Easier to setup a large network Cheaper to setup a network Flexibility Disadvantages Wireless Interference Not as fast (often) Not as secure (packets sniffer)