HW 5 Hints

UDP receiver signal-driven I/O version
PROBLEM 2) You may need to use '-s [packet size]' option of tcpdumpwrap so that the tcpdump captures up to [packet size] bytes from each packet. tcpdump uses the pcap library (i.e., libpcap) to capture and save the packet traces. Google for the format of pcap files to find out where the timestamps are stored in packet traces. Never assume that the size of IP or TCP header is 20 bytes; either or both may have optional fields. TCP might use window scaling option; search about the TCP window scaling option so that you can read off the correct initial window size from packet traces.
PROBLEM 3) Look at /u/u9/park/pub/cs422 to find talk_server.c and talk_client.c
PROBLEM 3) In Linux, stdin is buffered; getchar() like functions won't return until the enter is pressed. In Windows platform, kbhit() function in "co nio.h" does detect every key stroke. Google for kbhit() implementation for linux to find out how to set stdin to unbuffered mode.