Layer 4: the transport layer, transfers data across a network and provides error-checking mechanisms and data flow controls. 

Layer 3: the network layer, moves data into and through other networks.

Layer 2, the data link layer, handles problems that occur as a result of bit transmission errors.

Layer 4: the transport layer, transfers data across a network and provides error-checking mechanisms and data flow controls. 

Layer 3: the network layer, moves data into and through other networks.

Layer 2, the data link layer, handles problems that occur as a result of bit transmission errors.