Data Link Layer design issues
The data link layer is supported to carry out many specified functions. For effective data communications between two directly connected transmitting and receiving stations the data link layer has to carry out a number of specific function like:
1. Services Provided to the Network Layer : A well defined serve interface in the network layer. The principle service is transferring data from the network layer on source machine to the network layer on destination machine.
2. Frame Synchronization : The source machine send data in blocks called frames to be the destination machine. The starting and ending of each frame should be recognized by the destination machine.
3. Flow Control : The source machine must not be send data frames at a rate faster then the destination machines must be can accepted them.
4. Error Control : The errors mode in bits during transmission from source to destination machines must be detected and corrected.
5. Addressing : On a multipoint line, such as many machine connected together (LAN), the identity of the individual machine must be specified while transmitting the data frames.