Basic of UNIX System and Linux system

UNIX SYSTEM
UNIX is earliest and most widely used network Operation system.
It is available is many versions like Sun Solaris, HP, UNIX, AIX UNIX, and BSD. Though developed for different hardware platforms they all have similar networking features.
LINUX SYSTEM
Linux is an open Source networking Operation System based on UNIX architecture.
Linux provide flexibility to users for altering it according to there individual requirements.


Feature of Linux / UNIX
Security: it supports different levels of access permission for each user file and directory. So unauthorized user can not access a file beyond a certain specified level.
Linux/Unix it treaded all the device treated as files.
It is provide Internet based service like mail, web browsing and transfer
Different protocol has been support FTP, SMTP, HTTP,HTTPS

Cellular Topology Network Topologies | Advantage vs Disadvantage

This is a wireless topology where geographical area is divided into cells or regions.
Advantage
Each cell is the center processes an individual device, which can move from one cell to another cell and receive signal.
So it does not need any reconfiguration,
Hence it is so flexible.
It is easy to install it only requires a central location with strong signals.
Disadvantage
It is very expansive to set up as it requires a central station and require satellite communication links for each cell.
When the central station is fail communication within the cell and other cells is disrupted completely. But other cell not affected.

Mesh Topologies Network Topologies | Advantage vs Disadvantage

These topologies consist of point –to-point connection between all the devices on the network.
Advantage
Mesh topology provides increased Network stability and connectivity.
So it is providing flexibility.
It is highly suitable for large network connections as it allows multiple sites on the network.
These topologies provide high speed data transmission between source and destination device
Disadvantage
This is complex topology that often results in an increased amount of cabling.
This cost to install and is unsuitable for smaller organization.
It involve high maintains and is not easily manages.

Ring Topologies Network Topologies through Point-to-point | Token Ring | Advantage Disadvantage

Ring topology is connected through a point-to-point connection.
Devices are connected as a ring and data passes the ring in one direction like bidirectional and regenerated signal can be accessed by the next device.
Advantage
It prevents collisions and traffic by using what is called as the token-ring method.
Disadvantage
It is high risk failure as the devices are connected point-to-point and even if a single device malfunctions it stops the functioning of the entire network.
There cables are costliest cable network to setup.
Ring topology is easy to maintain and troubleshooting is simple as location of faults is very easy.

Star Topologies Network Topologies using Hub Advantage Disadvantage

Start topology connecting to the device over a network using hub.
Advantages
Star topology has the higher scalability,
Newer device can be added to the start-based network by attaching them to the hub.
Star topology is also easily maintained and the working of the hub is not affected If the device become defective
Disadvantage
However star topologies require a lot of cabling and as the hubs.
They are very expansive these have a high installation cost.

Bus Topologies Network Topologies CSMA/CD Advantage Disadvantage

Here the all the device connected through a shared cable often called the backbone.
The data packet sent to the all the device on the network through bus.
If the designation address on the packet matches it is own address the device read the data else it is ignore it.
The device knows as terminator that is attached to the end of the bus.
If the multiple devices transmit signals at the same time it may lead to a collision.
To avoid collision bus topology uses mechanism called as carrier sense Multiple Access (CSMA/CD)

Advantage
It is easy to install
It is requires minimum cabling
Low cost for setting up
Disadvantage
It is difficult to add more devices to a bus network that is already established.
An administrator difficulty in maintain and trouble-shooting such a topology



Networking Concept Computer Network | Network Topologies | Network Transmission Medium

Computer Network Concept
In computer Terminology a network is defined as a group of integrated that shares services, data, Information and interact with each other by means of communicating link.

Network Transmission Medium Concept
Network thus requires at least two devices connected through a physical medium called as the transmission medium. A transmission medium determines the speed and connectivity of the network


Network Topologies Concept
Different network arrangement known as topologies
In another words schematic representation of the arrangement of the device a network is called network topology. There are five categories in there topologies
Bus
Star
Ring
Mesh
Cellular