Performance analysis of data link layer protocols with a special emphasis on improving the performance of Stop-and-Wait-ARQ

The Data-Link Layer lies directly above the Physical Layer in the layered-network architecture. Three Protocols are in common use at the Data-Link Layer-Stop-and-Wait ARQ, Go-Back-N ARQ, and Selective-Repeat ARQ. Here, `ARQ' stands for Automatic Repeat Request. Stop-and-Wait ARQ suffers from limitations in its functionality and fails in a very specific case (lost acknowledgment). When the acknowledgement for a correctly received frame is lost in transmission, the sender assumes that the frame was not received correctly. When the timer times out, it retransmits the frame, which is then discarded by the receiver due to duplicacy. This process continues in an infinite loop [8]. The main aim of this paper is to introduce 3 different methods for eliminating this limitation. All the three solutions presented overcome the limitation described above, but with different side effects. However, in overall terms, all of them are an improvement over the existing STOP-AND-WAIT-ARQ.