CCNA Methods of Accessing the Media of Local Area Network

When two or more devices of network have to send data at the same time, contention of media is present. Some method type must be used for letting one device access at a time for the network media because simultaneous network communication on various devices is not possible; and it is done by passing the token and through collision detect/carrier sense multiple access, which are the two primary ways available.

Take note that the network media is the one being contended by devices for network in Ethernet which is a technology involving the use of collision detect / carrier sense multiple access, the one used by networks. The device listens first to check if the network is being used by another device when sending data is needed to be done and if the network is not in use, data sending begins.

For the device to see if there is another occurrence of a collision, it then again performs another listening task after transmission is done. When simultaneous sending of data by two devices occurs, there is a collision. Before the device sends its data again, a time with random length is awaited by an individual device as soon as a collision takes place. Take note that between two devices, a collision will not happen like in most instances.

There will be more collision to happen as the network becomes busier due to this contention type of network. As soon as the network devices increase, there is a fast degrading of the Ethernet’s performance. The token, frame of the network that is specially created, is passed from device to device within the network in the likes of Fiber Distributed Data Interface and Token Ring. Before sending a data, the device has to wait until the token is obtained.

For a network media be used by other devices upon completion of the transmission of data, the release of the token is important. Being deterministic is the primary advantage of networks that pass tokens which in the long run before the data is sent by a device, the passing maximum time is computed. At an estimated time frame, the communication line of the machinery in manufacturing company is in a location wherein it is working on a real time basis by using networks that pass tokens.

In the domains of various collision the network is segmented into switches for networks under collision detect / carrier sense multiple access that the devices number is reduced per individual segment of network for media to be contended.

Without the need of changes in addressing, there will be a significant increase in the network’s performance through the creation of domains that have collision which can said to be smaller. The networks under collision detect / carrier sense multiple access are half-duplex in a normal state, which at the time being, the information cannot be received as it is sent by the device. The other traffics are also being heard by the device as it talks and functions like a two-way radio.

An individual can start talking as the button for transmitting is pressed if he only likes to speak, and the frequency he is using can only be used by him as he talks, so no other person can speak on that time. The only time that the other person can speak is when the person using the frequency is done speaking and the button is transmitted.

The possibility of operation under complete duplex can be materialized upon the introduction of the switches. You can speak at the same as you listen because complete duplex functions like a regular home phone for calling. The mode of complete duplex can be operational in two devices at the same time when the network switch port is directly attached to a network device. Unlike to what others are claiming, one can increase the performance level when a device is set to mode of complete duplex. A data with Megabits per second of 200 is the transmitting load of an Ethernet segment with Megabits per second of 100, but for one direction traveling all at once, Megabits per second of 100 suffice.

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