08-10-2016, 03:29 PM
A network bridge is a computer networking device that creates a single aggregate network from multiple communication networks or network segments. This function is called network bridging. Bridging is distinct from routing, which allows multiple different networks to communicate independently while remaining separate. In the OSI model, bridging is performed in the first two layers, below the network layer (layer 3). If one or more segments of the bridged network are wireless, the device is known as a wireless bridge and the function as wireless bridging.
There are four types of network bridging technologies: simple bridging, multiport bridging, learning or transparent bridging, and source route bridging
A simple bridge connects two network segments, typically by operating transparently and deciding on a packet-by-packet basis whether or not to forward from one network to the other. A store and forward technique is typically used so, during forwarding, the packet integrity is verified on the source network and CSMA/CD delays are accommodated on the destination network. Contrary to repeaters that simply extend the maximum span of a segment, bridges only forward packets that are required to cross the bridge. Additionally, bridges reduce collisions by partitioning the collision domain.