Reliable Communication over Unreliable Channel

you will be building support for reliable communication over an unreliable link. We will keep some parts simple for now. For example, you will not have to worry about message ordering or receiving duplicate messages. To implement each BRP socket, we use the following: 1. One UDP socket through which all actual communication happen. 2. Two threads R and S. Thread R handles all messages received from the UDP socket, and thread S, handles the timeouts and retransmissions. More details of R and S are given below. 3. Two tables, unacknowledged-message table and received-message table. The first table contains the list of all messages that have been sent but not yet acknowledged by the receiver, along with the last sending time of the message. The second table contains all messages received in the socket. You will be implementing a set of function calls r_socket, r_bind, r_sendto, r_recvfrom , and r_close that implement BRP sockets. The parameters to these functions and their return values are exactly the same as the corresponding functions of the UDP socket, except for r_socket. The functions will be implemented as a library. Any user wishing to use BRP sockets will write a C program that will call these functions in the same sequence as when using UDP sockets.