Computer Network Topology

What is Topology

The physical topology of a network refers to the configuration of cables, computers, and other peripherals. Physical topology should not be confused with logical topology which is the method used to pass information between workstations.
Type of Network Topology :
Bus Topology

• Consists of two distinct and terminated ends
• Uses 'T' connector to connect a device
• Commonly used for 10Base5 and 10Base2 networks and is seldom used toda

Advantages

• Requires less cable

Disadvantages

• Difficult to move and change
• Single cable failure brings down the entire network
• Difficult to troubleshoot

Bus Topology

Ring Topology

• Each PC is connected directly to two other PC's
• Data Move one way
• Uses network token-passing access methods referred to as Token Ring.

Advantages

• Easy to troubleshoot

Disadvantages

• Expensive (use multiple cable)
• Single cable failure bring down the entire network

Ring Topology

Star Topology

• PC's are connected to a central point (hub, switch, access point)
• Commonly used for 10Base-T, 100Base-TX or 1000Base-T network

Advantages

• Single cable failure won't bring the whole network down
• Easy to troubleshoot
• Scalable

Disadvantages

• Expensive (multiple cable)
• Single point of failure (hub, switch)

Star Topology

Mesh Topology

• Path from every machine to every other machine
• n hosts = n(n-1)/2 connections
• Partial mesh don't incur quite the same expense in term of cabling but, of course, lose some of the redundancy

Advantages

• High fault tolerance

Disadvantages

• Very expensive, multiple cables

Mash Topology

Hybrid / Tree Topology

• Combination of two or more types of physical or logical network topology
  
  
  Hybrid / Tree Topology

Point-to-Point Topology

• Direct connection between two device
  

Point-to-Point Topology

Point-to-Multipoint Topology

• Connections between an interface on a router to multiple destination routers
  

Point-to-Multipoint Topology

Slow computer - how to fix it

Working with a slow computer can be time consuming as programs/ applications take a long time to start. This problem is more pronounced in computers which have been used for 6 or more months.

How to fix it

1.Check the programs running in the background. Most computer users need only a few basic programs but many other programs are loaded as a default by the computer manufacturer. Many antivirus programs run in the background and slow down the computer.

Run msconfig and remove all programs which are not used. You will have to reset the computer. Also go to add/remove programs and remove all non-essential software.

2. Defragment your computer hard drive. Click on the "My Computer" icon on the desktop. (for Windows XP) and run disk cleanup first. Then go to Tools and Defragment the hard disk drives (HDD) on your computer. It is advisable to defragment the HDD at least once a week, especially if large amounts of data are being downloaded from the internet. Delete all cookies and downloaded files.

3. Ensure that there is sufficient free space on the HDD where the operating system is loaded. Free space is required as virtual memory. Delete all unwanted files and transfer all large files / folders to other data storage media.

4. You may have a virus, spyware, trojan or adware on your computer. First remove all spyware, adware and then run a free antivirus program . Most viruses can be cleaned or quarantined by antivirus programs

5. Ensure that the latest device drivers are installed on your computer. The latest device drivers are usually available at both the computer and component manufacturers website. If you are not using a particular device, you can disable it

6. If your computer does not have sufficient memory or the memory is damaged, your computer will become slow, so try to add more memory. Windows XP needs at least 128 MB RAM, but 512 MB RAM is recommended for optimum performance.

7. If none of the above options work, you may have to reformat the hard disk and install the operating system again.