SWITCHING - BB

Switching is the method in which data is transmitted between nodes in order to reach its intended destination. There are 4 primary frameworks that are used to transmit and switch data.

CIRCUIT SWITCHING
This is one of the original methods of data transmission meaning that is fairly limited an has several issued. It was originally designed for voice/telephone communication and an issue with any node during transmission will severely slow down it down as the data only follows a established route. The method is split up into 3 stages:

1.Establish Route

-The node wanting to send the data contacts each of the nodes within it's route.

-The route is then locked off and can only be used for this transmission.

2.Transmit Data

-All of the data is sent at once through the single established route.

-The data does not stop at any of the nodes.

-The data is transferred at the slowest transmission speed between any of the nodes.

-The route cannot be accessed by any other nodes whilst the transmission is taking place.

3.Disconnection

-Once the correct number of acknowledgement signals are received by the original node sending the data, the route is opened up again to be accessed by other transmissions.

-Nodes may encounter an error where they believe that they are still being used so cannot be accessed until rebooted.

PACKET SWITCHING
A more widely used method within modern technology, the data being sent is broken down into individual data packets rather than being sent all at once. The header of each packet contains the address of the node that it needs to be sent to as well as any other information and data necessary for its transmission. At each node the packet is sent to the header is read and then sent to the next node that gets it closer to its destination. This method can perform something known as data rate conversion which is where the speed of transmission can change between nodes to become as fast as possible on the given channel.