CS330 01                            Assignment 3:  TCP/IP Network Programming

Develop TCP/IP client/server programs to simulate the full-duplex stop-and-wait data link protocol:

1. Write a connection-oriented File Server (FS) program to do the following:

a. Print the FS address (hostname, port_number, server name) on the screen.
b. Accept a connection request from the client.
c. Fork/Create a child process/thread to process the client request:
    Receive the file uploaded from the client in a number of data frames using the stop-and-wait protocol with Positive and Negative acknowledgment.
FRAME data structure used should be the same as your previous assignment.

2. Write a client program to do the following:

a. Connect to the FS server using the FS address printed on the screen.
b. Upload an image file to the FS server simulating the stop-and-wait protocol with
    Positive and Negative acknowledgment. Simulate the transmission errors by using random number generating function.
(Optional: To develop a full-duplex TCP connection on the client side so that it can send data packets and read acknowledgement at the same time by two different processes/threads.)

Protocol specifications:

a. Client and FS server communication should use the TCP/IP connection-oriented service.
The FRAME data size is limited to 512-byte and 1-bit sending window size should be used.
    You should use the sleep() function to simulate the transmission delay and message rate.
b. FS server must be a multi-process/multi-thread program to be able to serve multiple clients.
c. Assume the Data frames have 20% transmission errors, but they will not be lost.
    Short ACK/NACK frames will not have transmission errors. The server program will compute the checksum for simulating the transmission error.
   (Therefore no timer is needed to simulate this protocol.)
d. Using a random number generator (rand(...)) to simulate the transmission errors.

Compile the programs on cs1 using “gcc programName.c –lsocket –lnsl”

Testing

a. Start the FS server on a UNIX machine and print the FS server address on the screen.
b. Start the Client on a UNIX machine (optional on a machine other than the FS server machine) and then send the request to the FS server for uploading a large (at least 1MB) image file. (Find the FS server address from the text file.)

Assignment hand in policies

Write a Microsoft word report to describe the execution environment and run results (screen shots are required).
Email instructor the report and the programs source codes files on the due day.