PKS-Communicator-over-UDP-protocol

Design and implement an application using a custom protocol over the User Datagram Protocol (UDP) of the transport layer of the TCP/IP network model. The application will enable communication between two participants in a local Ethernet network, i.e., the transfer of text messages and any file between computers (nodes). The application consists of two parts: transmitting and receiving. The sending node sends the file to another node in the network. It is assumed that there is data loss in the network. If the sent file is larger than the user-defined maximum fragment size, the sending party breaks the file into smaller parts - fragments, which it sends separately. The user must be able to set the maximum fragment size so that they are not fragmented again on the lower layer. If the file is sent as a sequence of fragments, the destination node reports information about the message and whether the message was transferred without errors. When the entire file is received on the destination node, it will display a message about its reception and the absolute path where the received file was saved. The application must include communication error checking and re-requesting of erroneous fragments, including both positive and negative acknowledgement. After starting the program, the communicator automatically sends a packet to maintain the connection every 5 seconds until the user ends the connection. We recommend solving via self-defined signalling messages and separate thread.