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经典的数据链路层协议P1~P6的模拟器源代码和文档。最好在Linux下运行

This package simulates the protocols of Chapter 3 of "Computer Networks 3/e"
by Andrew S. Tanenbaum, published by Prentice Hall PTR, 1996.  It was written
by Andrew S. Tanenbaum and may be freely distributed.

The simulator is compiled by just typing 'make'.  If you want to use gcc
instead of cc, change the line

CC=cc

to

CC=gcc

in Makefile.

It is executed by giving a command line containing the simulation parameters.
The command line has six decimal parameters, as follows:

	sim  protocol  events  timeout  pct_loss  pct_cksum  debug_flags

where

        protocol tells which protocol to run, e.g. 5
        events tells how long to run the simulation
        timeout gives the timeout interval in ticks
        pct_loss gives the percentage of frames that are lost (0-99)
        pct_cksum gives the percentage of arriving frames that are bad (0-99)
        debug_flags enables various tracing flags:
		1	 frames sent 
		2	 frames received 
		4	 timeouts 
		8	 periodic printout for use with long runs 

For example

	sim 6 100000 40 20 10 3

will run protocol 6 for 100,000 events with a timeout interval of 40 ticks,
a 20% packet loss rate, a 10% rate of checksum errors (of the 80% that get
through), and will print a line for each frame sent or received.  Because
each peer process is represented by a different UNIX process, there is
(quasi)parallel processing going on.  This means that successive runs will
not give the same results due to timing fluctuations.

A set of possible student exercises is given in the file exercises.