Star Network

In a star network cable segments to a central connection unit or hub connect all computers.
Chief advantage of star topology over the bus topology over the bus topology is that, if a cable segment is broken, onlyonnected to the hub on that cable segment is affected.

Attachment Unit Interface (AUI)

Connector commonly are used with thick Ethernet cabling.  These device used a DB15 connecor to link o the network card.

Hardware utilized in a Bus Topology Network

Both thin Ethernet and thick Ethernet require the following additional network hardware to link the host.

1. BNC Connector
2. Terminator
3. AUI Connector

British Novel Connector-  BNC connector enable the various thin-net Coaxial cable segments to interconnect each host has a T-connector that is used to link the cable segment to a host computer.

Wiring standard in a Bus Network

Computer network commonly are linked using network cabling.  The following are two wiring standards for communications on a bus network.

10Base2-  Also known  as thin Ethernet.  It allow network segment up o 185 meter on coaxial cable.

10Base5-  Also known as thick Ethernet, it allows network segments up o 500 meter in coaxial cable.

Local Area Network

There are basic type of local area network.

1. Peer to Peer
2. Server Based

Peer to Peer-  Peer to Peer network operate with no dedicated server on the network.  Each host functions as both a client and a server.  The user at each host determine what information or peripherals he is willing to share with the other members of the network.  Peer to Peer network generally are related to smaller organizations they do not scale will to larger ones.

Server Based Network-  At least one host is dedicated to server functionality.  Client computer do not share any information with other computer.  All data is stored on the central server .  Most corporate networks are based on this methodology.  Within a server based network, server can play several roles these roles include the following.

Directory Server-  These provide a central directory service for management of users groups and host object to allow for centralized authorization using the central directory.

Files and Print Server-  These provide a secure repository for all data.  They also can  manage point queues that provide access to network.  Searchable print resources.

Application Server-  These provide the server side of client/server application.  In a client/server environment, the client run a small version of the program that allow connectivity to the server.  The server side of the application is used to perform processor- intensive quires on behalf of the client.  Example of application server included Web server and database server.

Mail Server-  These provides electronics message capabilities for the clients of the network.

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A mail server is a program responsible for receiving routing and delivering e-mail message.

Security Server-  These provide security to the local network.  If it is connected to any larger networks such as the internet, security; server include firewalls and proxy servers.

Remote Access Server-  These enalble external data flow to occur between the network, or alternatively, use the technology known as tunneling or virtual private networks (VPNs) to connect to the remote network over a public network such as the internet.