Services provided by Data Link Layer
One of the most essential functions of the Data Link layer is to provide an interface to the Network Layer. Its aim is to transmit data frames that it received, to the destination machine, so that the data frames can be handed to the Network Layer of the machine.
The services provided are as follows:
- Unacknowledged connectionless service
In Unacknowledged connectionless service, the source machine transmits independent frames to the destination machine without needing the machine to acknowledge these frames.
There is also no communication established by the sending or receiving machine before or after data transfer.
- Acknowledged connectionless service
In acknowledged connectionless service, each frame that is transmitted by the Data Link layer is acknowledged individually. There is no logical connection established, and the sender knows if the frames are transmitted safely or not.
It provides means by which the user of the Data Link can just send or transfer data and request return of data at the same time.
- Acknowledged connection oriented service
In acknowledged connection oriented service, a connection is established between the sender and receiver before the data is transmitted. After that, the data is transferred along the established connection.