Ethernet

Ethernet

what is Ethernet:

"Ethernet is a standard communications protocol embedded in software and hardware devices, intended for building a local area network (LAN). "

In Ethernet each computer is connected by means of a cable cable called Ethernet cable .An Ethernet cable is one of the most popular forms of network cable used on wired networks. Ethernet cables connect devices on local area networks such as PCs, routers and switches.Ethernet is the most commonly used LAN protocol. Ethernet uses a bus or star topology and supports data transfer rates of 10 Mbps.It uses high speed network cable and bus topology. Ethernet uses the CSMA/CD access method to handle simultaneous demands. All computer inn Ethernet use same cable to send and receive data they must follow same rule of communication. if they don't follow the rules data collosion may occur and data might be lost

CSMA/CD:

Carrier Sense Multiple Access/Collision Detect (CSMA/CD) is the protocol for carrier transmission access in Ethernet networks. If two or more computers transmit data at the same time the message can be lost .A computer checks if the cable is in use before transmitting data the computer waits if the cable is being used if starts transmitting data when the cable is free.

Advantages of Ethernet

• Easy to Install :Ethernet is easy to install its simple
• Noise Immunity :The coaxial cable used in a Ethernet network is very well 
  shielded, and has a very high immunity from electrical 
  noise caused by outside sources
• Relatively Inexpensive: Due to the simplicity inherent in the design of Ethernet, it can be an inexpensive technology to implement

Disadvantages of Ethernet :

• Difficult To Change: Reconfiguring a ethernet is somewhat difficult to do once 
  it is in place. Any changes to the network will result in 
  at least some "down time," as the bus must be broken and a 
  new section spliced in at the point of the break.
• Fault Intolerant:
  If any device or cable section attached to the network 
  fails, it will most likely make the entire network go down.
• Difficult Troubleshooting 
  Ethernet networks are very difficult to troubleshoot. There 
  is no easy way to determine what node or cable section is 
  causing a problem, and the network must be troubleshot by 
  a "process of elimination." This can be very time consuming.
• Specialized Cable  The RG-58A/U coaxial cable used in Ethernet networks can 

not be used for any other purpose. In the event that the 
network is changed to another type, then the cable will 
have to be replaced.