We don’t want any other person to start speaking at the same time, don’t want anyone else to disturb or interrupt us during our speaking etc.
Let us take the more realistic case.Ĭonsider yourself speaking in an assembly. When nodes or stations are connected and use a common link, called a broadcast link, we need a multiple access protocol to coordinate access to the link. In the case of a dedicated link (PPP network), there is no need for the lower layer.
The upper sublayer is basically responsible for the data link control, and the lower sublayer is responsible for resolving the access to the shared media. Datalink layer is divided into two functionality-oriented sublayers i.e The other users connected to this medium should wait. In a broadcast network, the single communication channel is to be allocated to one transmitting user at a time.
