The Scope of Computer Science: Part 2

Understanding the Computer Learning Environment

Network Topologies

Computer Network Topology – Mesh, Star, Bus, Ring and Hybrid

Geometric representation of how the computers are connected to each other is known as topology. There are five types of topology – Mesh, Star, Bus, Ring and Hybrid.

Types of Topology

There are five types of topology in computer networks:

1. Mesh Topology

2. Star Topology

3. Bus Topology

4. Ring Topology

5. Hybrid Topology

Mesh Topology

In mesh topology each device is connected to every other device on the network through a dedicated point-to-point link. When we say dedicated it means that the link only carries data for the two connected devices only. Lets say we have n devices in the network then each device must be connected with (n-1) devices of the network. Number of links in a mesh topology of n devices would be n(n-1)/2.

Advantages of Mesh topology

1. No data traffic issues as there is a dedicated link between two devices which means the link is only available for those two devices.

2. Mesh topology is reliable and robust as failure of one link doesn’t affect other links and the communication between other devices on the network.

3. Mesh topology is secure because there is a point to point link thus unauthorized access is not possible.

4. Fault detection is easy.

Disadvantages of Mesh topology

1. Amount of wires required to connected each system is tedious and headache.

2. Since each device needs to be connected with other devices, number of I/O ports required must be huge.

3. Scalability issues because a device cannot be connected with large number of devices with a dedicated point to point link.

Star Topology

In star topology each device in the network is connected to a central device called hub. Unlike Mesh topology, star topology doesn’t allow direct communication between devices, a device must have to communicate through hub. If one device wants to send data to other device, it has to first send the data to hub and then the hub transmit that data to the designated device.

Advantages of Star topology

1. Less expensive because each device only need one I/O port and needs to be connected with hub with one link.

2. Easier to install

3. Less amount of cables required because each device needs to be connected with the hub only.

4. Robust, if one link fails, other links will work just fine.

5. Easy fault detection because the link can be easily identified.

Disadvantages of Star topology

1. If hub goes down everything goes down, none of the devices can work without hub.

2. Hub requires more resources and regular maintenance because it is the central system of star topology.

Bus Topology

In bus topology there is a main cable and all the devices are connected to this main cable through drop lines. There is a device called tap that connects the drop line to the main cable. Since all the data is transmitted over the main cable, there is a limit of drop lines and the distance a main cable can have.

Advantages of bus topology

1. Easy installation, each cable needs to be connected with backbone cable.

2. Less cables required than Mesh and star topology

Disadvantages of bus topology

1. Difficultly in fault detection.

2. Not scalable as there is a limit of how many nodes you can connect with backbone cable.

Ring Topology

In ring topology each device is connected with the two devices on either side of it. There are two dedicated point to point links a device has with the devices on the either side of it. This structure forms a ring thus it is known as ring topology. If a device wants to send data to another device then it sends the data in one direction, each device in ring topology has a repeater, if the received data is intended for other device then repeater forwards this data until the intended device receives it.

Advantages of Ring Topology

1. Easy to install.

2. Managing is easier as to add or remove a device from the topology only two links are required to be changed.

Disadvantages of Ring Topology

1. A link failure can fail the entire network as the signal will not travel forward due to failure.

2. Data traffic issues, since all the data is circulating in a ring.

Hybrid topology

A combination of two or more topology is known as hybrid topology. For example a combination of star and mesh topology is known as hybrid topology.

Advantages of Hybrid topology

1. We can choose the topology based on the requirement for example, scalability is our concern then we can use star topology instead of bus technology.

2. Scalable as we can further connect other computer networks with the existing networks with different topologies.

Disadvantages of Hybrid topology

1. Fault detection is difficult.
2. Installation is difficult.
3. Design is complex so maintenance is high thus expensive.

Computer Laboratory Care and Maintence

But, before we dwell on the purpose of preventative maintenance let us first consider the basic question of what is computer hardware and what is in the preventative maintenance program.

WHAT IS COMPUTER HARDWARE?

All the physical components of the computer are hardware. This will include your keyboard, hard drives, internal CD or DVD drive, fans, etc. All of these components are included in computer hardware maintenance.

WHAT IS INCLUDED IN PREVENTATIVE MAINTENANCE?

Most people believe that preventative maintenance programs are only for the visible components of the computer. That is not true. Computer hardware maintenance also includes the not-so-visible components of the computer.

Typically, you perform preventative maintenance at the system level and physical level.

PHYSICAL LEVEL MAINTENANCE:

This is where you clean the physical components of the computer. Clean the keyboard to ensure that you remove the dust sitting between the keys. It’s important to remove and clean the fans that help maintain CPU temperature. Also, wipe off the monitor and blow out the dust sitting inside the CPU.

Make sure you complete this entire cleaning process carefully. Using any type of liquid or solvent can cause damage to the physical parts. Instead, it is important to use a soft cloth and right type of solvent. During the maintenance process, do not expose the physical components to extreme temperature changes.

SYSTEM LEVEL MAINTENANCE:

System-level maintenance ensures that your operating system runs in an optimized manner. Check your hardware drivers and download and install their latest versions. If you’re using any software, then it is best to have the upgraded and latest versions. There are also a lot of programs in your system that you do not use. Remove these programs and clean up the disk space so you can install more useful programs.

Most of the computers today have anti-virus and anti-malware protection installed. However, these are often outdated and do not have the updated security patches. This can pose a substantial threat to your operating system. Hence, they are also updated to the latest versions.

A lot of people make the mistake of not fragmenting their hard drive. This can cause a major data loss in adverse situations and even cause system slowdown. So, defragment your hard disk and create multiple drives.

WHY HARDWARE MAINTENANCE IS IMPORTANT

Now that we have seen how to take care of your computer, let us see why it important to have a periodic maintenance program.

ADDRESS ISSUES BEFORE THEY BECOME PROBLEMS

Maintenance activity helps you detect latent issues with your computer that can grow into major problems if not addressed in a timely manner. It can also impact the performance of your computer and give you sub-optimal output. Periodic maintenance helps you detect these problems at a system and physical level and address them immediately.

PREVENT SECURITY THREATS

Anti-virus and anti-malware software undergo an update process that ensures your computer has the highest level of protection against security threats. You don’t want to fall prey to a security vulnerability that can lead to business loss.

IMPROVE SPEED

Defragmenting the hard drive, removing unnecessary programs, and updating system drivers improve the operating speed of your computer.

OPTIMIZE EFFICIENCY

With time, computers tend to slow down and become sluggish. It’s inevitable that software slows down and gives the sub-optimal output. Therefore, periodic maintenance can help address this and optimize the efficiency of the computer.

Designing a hardware maintenance calendar can depend on multiple things like the extent of the use of a computer, the type of process performed on the computer, etc. It can be complicated and overwhelming.

Get a professional to help you with your preventative maintenance. Contact Dynamix Solutions to see how we can help with your computer hardware maintenance.

To successfully work in the Computer Laboratory(Computer Learning Environment), there is need for the user to have a good understanding on how to use, maintain, and repair the devices found in the Computer Laboratory.

Understanding Types of Computer Ports

A Computer Port is an interface or a point of connection between the computer and its peripheral devices. Some of the common peripherals are mouse, keyboard, monitor or display unit, printer, speaker, flash drive etc.

The main function of a computer port is to act as a point of attachment, where the cable from the peripheral can be plugged in and allows data to flow from and to the device.

A computer port is also called as a Communication Port as it is responsible for communication between the computer and its peripheral device. Generally, the female end of the connector is referred to as a port and it usually sits on the motherboard or system unit.

In Computers, communication ports can be divided into two types based on the type or protocol used for communication. That is Serial Ports and Parallel Ports.

Serial Ports

A serial port is an interface through which peripherals can be connected using a serial protocol which involves the transmission of data one bit at a time over a single communication line. The most common type of serial port is a D-sub connector that carry RS-232 signals.

Parallel Ports

A parallel port, on the other hand, is an interface through which the communication between a computer and its peripheral device is in a parallel manner i.e. data is transferred in or out in parallel using more than one communication line or wire. Printer port is an example of parallel port.

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