Computer Network Training

IT (Internet technology) jobs require computer network training and certification.

CompTIA Network+

Computer Network Certification

To begin you should obtain the CompTIA A+ certification. Most employers are very familiar with the A+ cert and require all new employees to have it. A+ cert is even more highly regarded for entry level computer tech work than college degrees. Employers know that individuals with A+ certification can work on and fix computers. The next certification you should consider is the CompTIA Network+ which is also highly regarded in the IT field. After obtaining those two certs you should consider either the Microsoft MSCE track or the Cisco CCNA track. Either of these two highly prized certs can move you along quickly to the higher paying positions.

Computer Network Security

Network security has become a major concern, especially with wireless networks. Wireless needs extra security controls to assure good security, such as, MAC filtering and good encryption.

Computer Network Support

Good support is essential for monitoring, maintenance, and management. Network techs, analysts, and administrators are need to assure proper performance.

Computer Network Services

There are many network services that should be provided, such as, email, file, data, and application sharing, print sharing, and Internet access are the basics.

Computer Network Management

A good administrator can manage the network to assure only authorized individuals and services are available to appropriate individuals. Access should be limited and authorized only with proper credentials.

Computer Network Repair

Network repair is an ongoing concern. Cabling, hardware, and software may need periodic updates and replacing. Scheduling repairs to minimize work interruptions is an important concern.

Computer Network Maintenance

Network maintenance needs to be scheduled and performed. This will help to optimize hardware life and performance. Cleaning helps to reduce heat buildup that can shorten component life.

OSI Model

YouTube Video

The OSI Model is composed of seven OSI layers that make up the model. Each layer is important to understand for proper understanding of network concepts of data packet creation and control. The layers start with Physical layer and end with the Application layer. The first, second, and third OSI layer are important to know concerning the network equipment implemented at these layers. For example a switch is a layer 2 device and a router is a layer 3 device, but a some routers can be both a layer 2 and 3 device. See the YouTube video to learn more.

Physical Layer

The Physical layer is where the data is either put onto the media or received off the media. The media could be the network cable or wireless. The data is in the form of bits and is called Bits as the PDU (protocol data unit). These bits can be voltage levels that represent binary numbers of 1 or 0. They could also be light pules traveling on a fiber optic cable or radio wave pulses for a wireless network.

Data Link Layer

The Data Link layer is where framing of the data takes place. The Frame is the PDU name at this layer. The MAC (media access control) physical address is added or removed depending on which direction the data is traveling. The MAC address is used by switches to switch the data to the appropriate computer or node that it is intended for in a LAN (local area network).

Network Layer

The Network layer is where the IP (internet protocol) address is added or removed and the PDU at this layer is called a Packet. Routers operate at this level and use the IP (logical address) to route the data to the appropriate network. Network locations are found by the routers using routing tables to locate the appropriate networks.

Transport Layer

The Transport layer is where the data is segmented (broken into pieces) and used by the TCP protocol to ensure accurate and reliable data is transferred. The data segments are numbers so that proper sequencing can be determined on the receiving side in order to rebuild accurate files. The PDU name at this layer is called Segment.

Session Layer

The Session layer is where the session is created, maintained, and torn-down when finished.

Presentation Layer

The Presentation layer is where the data is formatted or decrypted into files that the user can understand.

Application Layer

The Application layer is the user interface to the network where that data is either being generated or received.

The study of Computer Network Training and the OSI Model can help you to prepare for certification and employment is this exciting field.

Network Topology

The study of Computer Network Training brings you first to the study of network topology which is the physical or logical way the networked computers are connected. You can have a physical Bus topology, physical or logical Ring Topology, physical Star Topology, or even a physical Mesh topology. The logical topology might be different than the physical topology in the way data packets are switched through the network.

Bus Topology

The Bus topology has a single cable that all the computers and devices are connected to. It is very simple to implement but not very fast or reliable. The maximum speed for Bus topology is 10 megabits per second using 10Base2 cabling. There is also a major draw back to the Bus because you create a single collision domain. When a computer trys to send packets on the Bus it will listen first to make sure the Bus is clear before sending oackets. However another computer could send packets at the same time creating a collison and no packets get through. The computers will time, count down, and then try again. Also if the cable breaks or a device is removed the signal traveling down the cable will reflect back and could interrupt the packets moving through the cable, which can bring down the entire network. Because of all the draw backs you will not see the Bus topology used with newer networks.

Ring Topology

The Ring topology was popularized by IBM and worked very well because using a token that traveled around the Ring eliminated collisions. Each computer would have an opportunity to use the token for sending or receiving data packets. There were two major problems with the Ring. First as you added more computers it would take longer to get the token and second the speed did not keep up with Ethernet so it lost popularity and you will rarely see it today.

Star Topology

The Star topology is by far the most popular and widely used for networks today. Switches are generally used as the central hub and provide individual collision domains between just 2 computers, which has reduced the packet collision problem and greatly increased the bandwidth and speed of the networks.

Mesh Topology

The Mesh topology is primarily used on the Internet. This allows several alternate paths for data to travel in case a segment or path goes down or becomes congested. The routers on the Internet are constantly measuring the speed of each segment or path and determining dynamically which is the better path for sending packets. This keeps the Internet very fast and responsive to changes that occur constantly each day as equipment is taken down for maintenance and repair and new equipment is installed to handle the growth.

Network topology is always a consideration when designing a new network. The Star topology will be the choice used and implemented for the LAN and possibly a Mesh topology for servers and other critical connecting devices, such as, routers that connect to other networks or the Internet.

Computer Network Training