Introduction to Networking

INTRODUCTION TO NETWORKING

Computer Network Defined

            College life is one hell of a kind experience. You encounter things that you have been ignorant before. And honestly, I faced some difficulty in one of my subjects, the I.T. 11. Ironically, my course is Information Technology and I have difficulty in the subject of my field. But with just some few adjustments, I learned new yet useful information that I can use and apply in my life as an I.T. Professional.

         A computer network is a set of computers connected together for the purpose of sharing resources. The most common resource shared today is connection to the Internet. Other shared resources can include a printer or a file server.
A computer network is a group of computer systems and other computing hardware devices that are linked together through communication channels to facilitate communication and resource-sharing among a wide range of users. Networks are commonly categorized based on their characteristics.A computer network is a set of connected computers. Computers on a network are called nodes. The connection between computers can be done via cabling, most commonly the Ethernet cable, or wireless through radio waves. Connected computers can share resources, like access to the Internet, printers, file servers, and others. A network is a multipurpose connection, which allows a single computer to do more.

Network Architecture

             Network architecture refers to the layout of the network, consisting of the hardware, software, connectivity, communication protocols and mode of transmission, such as wired or wireless. Know about the types ofnetwork classified according to the areas covered such as LAN, MAN and WAN.

               Network Architecture is the overall design of a computer network that describes how a computer network is configured and what strategies are being used. It also known as network model or network design

       Two main network architecture: 

Client/Server network

            is a network architecture in which each computer or process on the network is either a client or a server. Servers are powerful computers or processes dedicated to managing disk drives (file servers), printers (print servers), or network traffic (network servers ).

Peer-To-Peer network

             is a commonly used computer networking architecture in which each workstation, or node, has the same capabilities and responsibilities. It is often compared and contrasted to tCablinghe classic client/server architecture, in which some computers are dedicated to serving others.

Ethernet Cabling

     to connect all devices in your network. Most modern networks use Category 5 or 6 cabling, and you can purchase the cables in a variety of lengths. You can even buy cables in different jacket colors to distinguish network devices in a large network. For instance, you can use blue cables for PCs, red ones for servers, and so on.

Modem

     a combined device for modulation and demodulation, for example, between the digital data of a computer and the analog signal of a telephone line.

Router and Switches

           Routers might have a single WAN port and a single LAN port and are designed to connect an existing LAN hub or switch to a WAN. Ethernet mac aDDswitches and hubs can be connected to a router with multiple PC ports to expand a LAN.

MAC Address

         A media access control address (MAC address) is a unique identifier assigned to network interfaces for communications on the physical network segment. MAC addresses are used as a network address for most IEEE 802 network technologies, including Ethernet and WiFi.

            Communication Device

 Hub  

• A non-intelligent device, and has no decision making capability .Take the input data from one of the ports and broadcast the information to all the other ports connected to the network. 

 

Repeaters A repeater is a device similar to the Hub, but has additional features. Used in places where amplification of input signal is necessary Regenerates Faded Signals
Switch A switch is an intelligent device .Has a decision making capacity
Bridges A device that connects two local-area networks (LANs), or two segments of the same LAN that use the same protocol
Routers A router is a device that forwards data packets along networks. A router is connected to at least two networks, commonly two LANs or WANs or a LAN and its ISP's network.
NIC(Network Interface Card)  So that the computer can be connected to a network.

                                       Physical Topology

         Computer networks can be broken down historically into topological, which is a technique of connecting computers. The most common topology today is a collapsed ring. This is due to the success of a network protocol called the Ethernet. This protocol, or a network language, supports the Internet, Local Area Networks, and Wide Area Networks.

Star Topology

            A star topology is a design of a network where a central node extends a cable to each computer on the network. On a star network, computers are connected independently to the center of the network. If a cable is broken, the other computers can operate without problems. A star topology requires a lot of cabling.

Bus Topology

          A bus topology is another type of design where a single cable connects all computers and the information intended for the last node on the network must run through each connected computer. If a cable is broken, all computers connected down the line cannot reach the network. The benefit of a bus topology is a minimal use of cabling.

 Ring Topology

          A similar topology is called a ring. In this design, computers are connected via a single cable, but the end nodes also are connected to each other. In this design, the signal circulates through the network until it finds the intended recipient. If a network node is not configured properly, or it is down temporarily for another reason, the signal will make a number of attempts to find its destination.

A collapsed ring is a topology where the central node is a network device called a hub, a router, or a switch. This device runs a ring topology internally and features plugins for cables. Next, each computer has an independent cable, which plugs into the device. Most modern offices have a cabling closet, or a space containing a switch device that connects the network. All computers in the office connect to the cabling closet and the switch. Even if a network plug is near a desk, the plug is connected via a cable to the cabling closet.

Mesh Topology

         A network setup where each computer and network device is interconnected with one another, allowing for most transmissions to be distributed, even if one of the connections go down. This topology is not commonly used for most computer networks as it is difficult and expensive to have redundant connection to every computer. However, this topology is commonly used for wireless network. Below is a visual example of a simple computer setup on a network using a mesh topology.

   There are two types of mesh topologies:

Full mesh topology: occurs when every node has a circuit connecting it to every other node in a network. Full mesh is very expensive to implement but yields the greatest amount of redundancy, so in the event that one of those nodes fails, network traffic can be directed to any of the other nodes. Full mesh is usually reserved for backbone networks.

Partial mesh topology: is less expensive to implement and yields less redundancy than full mesh topology. With partial mesh, some nodes are organized in a full mesh scheme but others are only connected to one or two in the network. Partial mesh topology is commonly found in peripheral networks connected to a full meshed backbone

TREE Topology

           It has a root node and all other nodes are connected to it forming a hierarchy. It is also called hierarchical topology. It should at least have three levels to the hierarchy.

HYBRID Topology

It is two different types of topology which is a mixture of two or more topology. For example if in an office in one department ring topology is used and in another star topology is used, connecting these topology will result in Hybrid Topology (ring topology and star topology).

There are two types of network, the Metropolitan Area Network and the Wide Area Network.

           First, let’s talk about the Metropolitan Area Network or what others call as MAN. It is a high speed network that connects local area network in Metropolitan Area such as city or town and handles bulk of communication activity across the region. A MAN typically includes one or more LAN but covers a smaller geographically area than a WAN.                                   
                  The WAN or the Wide Area Network is a network that covers a large geographically area such country or the world. WAN combines many types of media such as telephone lines, cables and radio wave.

Network Architecture is the overall design of a computer network that describes and shows a computer network is configured and what strategies are being used. It also known as network model or network design.

            

A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, or office building.