1. Growing the Network © 2004 Cisco Systems, Inc. All rights reserved. Choosing the Right Network Topology INTRO v2.0—3-1

2. © 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—3-2 Outline Overview Physical vs. Logical Topologies Bus Topology Star and Extended-Star Topologies Ring Topologies Mesh and Partial-Mesh Topologies Wireless Networks Summary

3. © 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—3-3 Physical Topology Categories

4. © 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—3-4 Logical Topologies

5. © 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—3-5 Bus Topology All devices receive the signal

6. © 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—3-6 Star Topology Transmissions go through a central point Single point of failure

7. © 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—3-7 Extended-Star Topology More resilient than star topology

8. © 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—3-8 Ring Topology Signals travel around ring Single point of failure

9. © 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—3-9 Dual-Ring Topology Signals travel in opposite directions More resilient than single ring

10. © 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—3-10 Full-Mesh Topology Highly fault tolerant Expensive to implement

11. © 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—3-11 Partial-Mesh Topology Trade-off between fault tolerance and cost

12. © 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—3-12 Wireless Network

13. © 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—3-13 Summary A physical topology describes the layout for wiring the physical devices, while a logical topology describes how information flows through a network. In a physical bus topology, a single cable effectively connects all the devices. In a physical star topology, each device in the network is connected to the central device with its own cable. When a star network is expanded to include additional networking devices that are connected to the main networking device, it is called an extended-star topology.

14. © 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—3-14 Summary (Cont.) In a ring topology, all the hosts are connected in the form of a ring or circle. In a dual-ring topology, there are two rings to provide redundancy in the network. A full-mesh topology connects all devices to each other, while in a partial-mesh topology, at least one device has multiple connections to other devices. Instead of cables, wireless communication uses RFs or infrared waves to transmit data between devices on a network. Some common applications of wireless data communication include accessing the Internet using a cellular phone, home or business Internet connection over satellite, sending data between two hand-held computing device, and using a wireless keyboard and mouse for the PC.