2. Network Devices By Scott Burden & Linnea Wong

3. Hubs Intelligent hubs have console ports, to allow monitoring of the hubs status and port activity. Passive hubs just repeat any incoming signals to every port available, therefore does not act as a line repeater. Passive hubs just split signals to multiple ports but do not regenerate the signals, which means that they do not extend a cable’s length. They only allow two or more hosts to connect to the same cable segment. Active hubs regenerate signals. Hubs utilise star topology.

4. Hub Pros & Cons Disadvantages Bandwidth is shared by all hosts i.e. 10Mbs shared by 25 ports/users. Can create bottlenecks when used with switches. Have no layer 3 switching capability. Most Hubs are unable to utilise VLANS. Advantages As an active hubs regenerate signals, it increases the distance that can be spanned by the LAN (up to 100 meters per segment). Hubs can also be connected locally to a maximum of two other hubs, thereby increasing the number of devices that can be attached to the LAN. Active hubs are usually used against attenuation, which is a decrease in the strength of the signal over distance.

5. Switches A switch is a multi-port bridge. It operates at OSI data link layer 2. It stores MAC addresses in an internal lookup table. Temporary switched paths are created between the frame’s source destination. Some Switches have limited layer 3 IP routing capabilities. Switches can be configured to use VLANS. Switches support spanning tree protocol to create resilient networks.

6. Example Topology Switch Hub UTP 10Mbs Fibre 100Mbs

7. Transceiver Modules Connects to any Auxiliary Unit Interface port (AUI). Operates at OSI layer 1. Allows multiple media types to connect to an Ethernet device. i.e. fibre ST/SC,Co-ax cable, and UTP. UTP Co-axial

8. Routers Routers are OSI network layer 3 devices Using interface modules can connect different layer 2 technologies e.g. Ethernet, FDDI, token ring etc… Routers have the capability to interconnect network segments or entire networks (WANS/MANS). These devices examine incoming packets to determine the destination address of the data. It then examines its internal routing table to choose the best path for the packet through the network, and switches them to the proper outgoing port.

9. Example Router Topology

10. THE END!!