Discussion Assignment 6 PDF

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Assignment Unit 6...

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Consider a simple application-level protocol built on top of UDP that allows a client to retrieve a file from a remote server residing at a wellknown address. The client first sends a request with a file name, and the server responds with a sequence of data packets containing different parts of the requested file. To ensure reliability and sequenced delivery, client and server use a stop-and-wait protocol. Ignoring the obvious performance issue, do you see a problem with this protocol? Think carefully about the possibility of processes crashing. First, we need to consider that; a simple application level protocol is implemented on top of User Datagram Protocol, the client transmits a request with a file name and the server responds with a sequence of data packets, which contain the requested file, the server and the client are using the stop and wait protocol to ensure the reliability in data delivery, and that the protocol allows client to retrieve a file from a remote server exist in a known address path. Yes, there is a problem with the protocol because, the listed consideration above will make it possible for the client to fetch a wrong file. For instance, if two clients 1 and 2 are available and client 1 made a request for a file (file a) which crashed, if client 2 made use of the same protocol to request some other file (file b). Certainly, the client 2 is running on the same machine with client 1, which made both to use the same IP address. If for example, client 2 request is lost while the server is responding to client 1, then the client 2 also receives the same responds from server which is made for client 1, assuming that it is a reply for its own request which was earlier lost....