Networking Types

Hi guys in this topic we going to see about networking types. Basically they are classified into 5 types,

• LAN - Local Area Network
• CAN -Campus Area Network
• MAN -Metropolitan Area Network
• WAN - Wide Area Network
• SAN - Storage Area Network

LAN

  A network that is limited to a relatively small area such as a campus or a single building (up to 2 km) is called LAN. Sometimes called as Single Location Network. Mainly LANs are designed to allow resources to be shared between personal computers or workstations.

The following characteristics differentiate one LAN from another

•         Topology - It defines structure and geometric arrangement of devices on the network.
•         Protocols - The rules and encoding scheme for sending data. It defines whether to use peer to peer or client-server architecture.
•         Media - It can be either cables or fiber optics.

LAN can uses following devices to share data Hub, Switch Bridge, Repeater, Router. 

CAN

       To connect different LAN in a campus or a building is known as campus area network for example colleges, hospitals, universities etc..

MAN

      A network that connects two or more LANs but does not extend beyond the boundaries i.e. area inside town or city not exceed 50 km`

WAN

    A wide area network provides long distance transmission of data, image, audio and video information over large geographic area. It allow access over serial interfaces operating at lower speeds. It connect devices using Router, Modem, Communication server etc. It usually uses transmission facilities provided by telephone companies.

SAN 

  A SAN is a dedicated, high performance network used to move data between servers and storage resources. Because it is a separate, dedicated network, it avoids any traffic conflict between clients and servers.

Ring Topology, Hybrid Topology and Wirless Topology

Hi friends now we discuss about ring and hybrid topologies in detail.
  
RING TOPOLOGY
A ring topology connects one host to the next and the last host to the first. This creates a physical ring of cable. A signal is passed along the ring in one direction from device to device, until it reaches the destination. Each devices can incorporates with the repeater.

Advantages

• It is easy to install and reconfigure.
• It is very organized. Each node gets to send the data when it receives an empty token. This helps to reduces chances of collision. Also in ring topology all the traffic flows in only one  direction at very high speed.
• Even when the load on the network increases, its performance is better than bus topology.
• There is no need for network server to control the connectivity between workstations.
• Additional components do not affect the performance of network.
•  Each computer has equal access to resources.

Disadvantages

• The traffic is unidirectional.
• Any break in the ring can cause entire network failure.
• Network is highly dependent on the wire which connects different components.

 HYBRID TOPOLOGY

The combination of two or more topologies is called hybrid topology. In this example we use star, bus and ring topologies.

Advantages

• Reliable : Fault detection and troubleshooting is easy in this type of topology. 
• Scalable: Its easy to increase the size of network by adding new components, without disturbing existing architecture.
• Flexible: Hybrid Network can be designed according to the requirements of the organization and by optimizing the available resources. Special care can be given to nodes where traffic is high as well as where chances of fault are high.
• Effective: Hybrid topology is the combination of two or more topologies, so we can design it in such a way that strengths of constituent topologies are maximized while there weaknesses are neutralized. 

Disadvantages

• Complexity of Design: One of the biggest drawback of hybrid topology is its design. Its not easy to design this type of architecture and its a tough job for designers. Configuration and installation process needs to be very efficient.
• Costly Hub: The hubs used to connect two distinct networks, are very expensive. These hubs are different from usual hubs as they need to be intelligent enough to work with different architectures and should be function even if a part of network is down.
• Costly Infrastructure: As hybrid architectures are usually larger in scale, they require a lot of cables, cooling systems, sophisticate network devices, etc.

 WIRELESS TOPOLOGY
A wireless topology is the one in which few cables are used to connect to the systems. The network is made up of transmitters that broadcasts the packets using radio frequencies. The networks contains special transmitters called cells or wireless access points. The Wireless networks therefore have only two topologies: infrastructure and adhoc. This is a direct and natural result of the non-physical nature of interaction of computers in a wireless network.

Advantages

• It reduces the cost of cabling.
• Troubleshooting failed devices and cells are easy.

Disadvantages

• It includes higher chances of signal interferences.
• Another main drawbacks is signal interception

Mesh Topology and Star Topology

Now we going to see about mesh and star topologies in detail.

MESH TOPOLOGY
In mesh topology, every device has a dedicated point-to-point link to every other devices. The dedicated link carries the traffic only between two devices it connects. To find the number of links connected to the mesh topology use this

                                                          n(n-1)/2

where n is number of devices.

Advantages

• It guarantees the each connection and thus eliminates the traffic problem.
• Even if one of the links fails there is always an alternative present. So data transfer doesn’t get affected.
• It provides privacy and security.
• Expansion and modification in topology can be done without disrupting other nodes.
  

Disadvantages

• There are high chances of redundancy in many of the network connections.
• Overall cost of the network is very high.
• Installation and maintenance of this topology is very difficult. Even administration of the network is tough.

STAR TOPOLOGY
In star topology, each device has a dedicated point-to-point link connected to the central controller mainly called hub. The devices are not directly linked to the other devices.

Advantages

• It is less expensive than mesh topology.
• It has better performance. Performance of the network is dependent on the capacity of central hub.
• Easy to connect new nodes or devices.
• Centralized management. It helps in monitoring the network.
• Failure of one node or link doesn’t affect the rest of network. At the same time its easy to detect the failure and troubleshoot it.

Disadvantages

• The dependency of whole topology is on central device. If it fails whole network goes down.
• The use of hub, a router or a switch as central device increases the overall cost of the network.
• Performance and as well number of nodes which can be added in such topology is depended on capacity of central device.

Network Topology

Now we going to see about topology and its types. Network topology defines the structure of the network.One part of the topology definition is the physical topology, which is the actual layout of the wire or media. The other part is the logical topology, which defines how the media is accessed by the hosts for sending data.

Physical Topology

• It refers to the interconnected structure of a local area network (LAN). 
• It is created to record where each hosts is on the network.
• The method employed to connect the physical devices on the network with cables, media etc.

Logical Topology

• It is a concept in networking that defines the architecture for communications in all nodes of the network.
• It shows how the host (computer) uses the network, host names, addresses, groups, applications.
• Using routers and switches the logical topology of the network can be dynamically maintained and reconfigured.

The network topologies are classified into following types

• Bus Topology
• Star Topology
• Mesh Topology
• Ring Topology
• Hybrid Topology
• Wireless Topology

BUS TOPOLOGY
 
A bus topology is a single backbone cable that is terminated at both ends. All the hosts are directly connected to the backbone.

Advantages

• It is easy to set-up and extend bus network.
• Cable length required for the topology is least compared to other network.
• Cost is less.
• It is good for LAN.

Disadvantages

• Difficult reconnection and fault isolation.
• If the main cable encounters problem, then whole network will breaks down.
• Proper termination is required to dump signals. Use of terminators is must.
• It is difficult to detect and troubleshoot fault at individual station.
• Maintenance costs is high.
• Efficiency of Bus network reduces, as the number of devices connected to it increases.
• It is not suitable for networks with heavy traffic. 
•  Security is very low because all the computers receive the sent signal from the source.

Transmission Types

Now we can see about network transmission types in detail. Communication between devices can  be  done by following ways

• Simplex
• Half-Duplex
• Full-Duplex

Simplex

   It is a one way transmission i.e the communication is unidirectional. Only one device can transmit and others can receive it. We can either send information or receive information using this mode. Keyboards and monitors are best example for simple mode.

      Ex: Cable connection

Half-Duplex

   It is two way communication but one at a time. When one device is sending ,the others can only receive and vice versa.

      Ex: Walkie - Talkie
When a person A talking in walkie-talkie person B will listen then person B will talks means person A will listen.

Full-Duplex

   It is two way communication i.e both devices can transmit and receive simultaneously. One common example is telephone network, when two people are communicating by a telephone line both will listen and talk at the same time

      Ex: Internet, Mobile

 

Basics of Networks

This blog contains information about the networking related concepts with clear explanation. Data communication and networking are changing the world even more easy to access, distribute accurate information's. Computer network supports various applications to access world wide web(www) for sharing printers, faxes, server etc..

Definition

A computer networks means connecting two or more devices to share data. Data is transferred in the form of packets. The connection between network is done by either Wired or Wireless medium. There are two things to setting up a networks; the hardware used to connect the system together and the software installed on the computers to allow them to communicate. Nowadays computer networks become core of communication.  The network hardware is made by 2 components: 

1. The entities that want to share the information or resources.
2. The medium that enables to communicate.

The networks can be classified into two types

• Peer to Peer Network
• Client-Server Network

Peer to Peer Network

In this, individual users can control their resources (i.e) it has no dedicated servers instead, a number of workstations are connected together to share data.

Client-Server Network

In this network services are located on a dedicated computer is called server. The client can send request to the server in which it can respond to the client.