Backnones
Signal flow and data transfer are assisted with in a network by various devices known as backbones.
The four different backbone devices are
1.hubs 2.Bridges 3.Switches 4.Gateways
Each device transports data in a specific way.
What is a hub?
A hub is a centralized connecting device often located at a center of star network.That automatically rebroadcast any signal or data that it receives from one device to all other devices on the network. Because all the devices connected to a hub are competing for media usage.Its possible for collision to occur when two devices send transmissions simultaneously.For this it is important to avoid using a hub for messaging that require immediate response.
What is a Bridge?
Network bridges are smart devices that process and record information about signal traffic between the devices in the networks.The bridge then uses this information to determine the most efficient path for data transfer between a transmitting and receiving device without having to send it to every device in the network.
What is a switch?
A switch is a multi port network bridge that uses packet switching to forward data to one or multiple specific devices. Because more than one transmission can occur at a time.Switch operating speeds are very fast.Switches are also full duplex devices that allow data signal to flow simultaneously in both directions.This eliminates the risk of data collision that may occur in other network backbone devices.
What is Gateway?
When two segments of the same network have different communication formats a gateway is needed to connect them. A gateway performs a conversion function so that a computer on an Ethernet network using a TCP/IP protocol may communicate with a PLC on a subnet using the controlnet protocol even though these two protocols are incompatible the gateway can connect them on the same network and allow them to function together