Understanding Information Systems and Network Topologies

1. Information System Definition and Functions

An information system is an organized system for the collection, organization, storage, and communication of information. It is the study of networks that people and organizations use to collect, filter, process, create, and distribute data. Essentially, it's a group of components that interact to produce information.

Objectives:

• Efficient management of data and information
• Improvement of business processes
• Creation of value

The main functions are:

• Capturing internal and external data
• Data processing
• Distributing information to users

2. Centralized vs. Distributed Information Systems

Centralized Systems

In a centralized system, all calculations are done on one particular computer.

Distributed Systems

In a distributed system, the calculation is distributed to multiple computers.

Architectures of Distributed Systems

Peer-to-Peer (P2P)

P2P is a commonly used computer networking architecture in which each workstation has the same capabilities and responsibilities.

Client-Server

Client-server is a network architecture where each computer on the network is either a client or a server. This type of architecture has one or more client computers connected to a central server over a network or internet connection.

Advantages:

• Improved data sharing
• Integration of services
• Shared resources amongst different platforms
• Data processing capability despite the location

Disadvantages:

• Overloaded servers
• Impact of centralized architecture

Three-Tier

Three-tier architectures move the client intelligence to a middle tier so that stateless clients can be used. This simplifies application deployment. Most web applications use this type of architecture.

3. Difference Between Networks

Bus Network

A bus network is designed with a sole communications channel to which several devices are connected. All devices share the same communication channel to share information.

Advantages:

• Works well for small networks
• The easiest network topology to implement
• Requires less cable length

Disadvantages:

• Can be difficult to identify problems if the whole network goes down
• Additional devices slow down the network
• If the main cable is damaged, the network is divided in two

Star Network

In a star network, stations are connected to a central point, and all communications must pass through this point. Its central node is always active and has resources to avoid problems.

Advantages:

• If one node breaks, it doesn't affect other connections
• Devices can be added or removed without disturbing the network

Disadvantages:

• Expensive network layout
• The central hub is a single point of failure for the network

Ring Network

In a ring network, each station is connected to another one, and the last one connects to the first one. Each station has a receptor and a transmitter that sends the signal to the next station.

Advantages:

• All data flows in one direction
• A network server is not needed
• Data can be transferred between stations
• Additional workstations can be added without impacting the network

Disadvantages:

• All data has to pass through all stations, which makes it slower
• If one workstation goes down, the entire network is affected
• The hardware has to be connected to each workstation

Tree Network

In a tree network, all nodes are connected as in a tree. It has a hub or switch where all nodes are connected. It is a variation of a bus network.

Advantages:

• Ease of network expansion

Mesh Topology

In a mesh topology, all nodes are connected with all other nodes. Communication interruption is not possible. Each server has a connection with the other servers.

Advantages:

• Each connection can carry its own data load
• Robust
• Faults are diagnosed easily
• Provides security and privacy

Disadvantages:

• Installation and configuration are difficult
• Cabling cost is high
• Bulk wiring is required