WWW traffic generator available

[Tom Henderson <tomh@kayak.CS.Berkeley.EDU>]

As part of our CS268 class project, we have ported over the http model in Bruce 
Mah's INSANE simulator.  We are using this code to generate background traffic
which looks like actual web traffic.  We've found that other people are 
interested in using this in their simulations.

At a high level, it works as follows:  There are two types of source agents:
WWWClient and WWWServer.  At configuration time, the WWWClient is connected
to the WWWServer.  The WWWClient makes a short request to the WWWServer, which
then generates a random number of connection responses, each with a random
length.  Once the WWWServer finishes sending the data to the WWWClient, the
WWWClient waits for a random time ("think time") before making another
request from the WWWServer.  Empirical distributions, derived from Bruce's 
web traces, dictate the random behavior.  

We do not intend to commit this work to the ns repository, since issues
regarding a general framework for distributions and traffic generation still
have not been finalized.  This is intended more as a short term implementation.

To obtain the tar file (which contains a more comprehensive README), see
http://http.cs.berkeley.edu/~tomh/software.html

The credit for the implementation is due to Emile Sahouria, who did most of
the work.  Questions or comments can go to emile@eecs or tomh@cs.

Tom and Emile