© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Growing the Network Choosing the Right Network Topology

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Outline Overview Physical vs. Logical Topologies Bus Topology Star and Extended-Star Topologies Ring Topologies Mesh and Partial-Mesh Topologies Wireless Networks Summary

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Physical Topology Categories

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Logical Topologies

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Bus Topology All devices receive the signal

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Star Topology Transmissions go through a central point Single point of failure

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Extended-Star Topology More resilient than star topology

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Ring Topology Signals travel around ring Single point of failure

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Dual-Ring Topology Signals travel in opposite directions More resilient than single ring

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Full-Mesh Topology Highly fault-tolerant Expensive to implement

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Partial-Mesh Topology Trade-off between fault tolerance and cost

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v Wireless Network

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v 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.

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v 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 devices, and using a wireless keyboard and mouse for the PC.

© 2005 Cisco Systems, Inc. All rights reserved.INTRO v