The udp server works on my Linux box. Its testing was not too thorough and
there is no reason to believe that it is perfect.

The server is made available for testing purposes and should not be left
running alone.

Specifically:
1. denial of service was not taken into account.
2. clever incorrect input may close the server.
3. retransmissions are done blindly with only the legal datagrams
retransmitted.
4. requests for url (through port 80) work only sometimes.

Some suggestions about testing your client:

1. Start with one object of small size (a few hundred bytes). It does not
have to be a pdf file (actually, it will be best if it is a text file).
This way you can check whether your client receives what is expected.

2. Use only local files at first.

3. Keep the SHUFFLE and LOST values as 0 until you need to test
retransmissions.

4. When a dmamaged sequence of datagrams arrives, you can ask for a
retransmission of datagrams that do not exist.