[ns] TCP receiver window advertisements

[Nimrod Mesika <nimrodme@bezeqint.net>]

It seems like all TCP implementations (FullTCP included) in ns2 lack
receiver window advertisements (i.e., they assume the receiver has
infinite input buffers).

I'm primarily interested in controlling the behaviour of the source by
modifying the advertised window. Therefore I don't need a 'correct'
implementation of the receiver side (TCPSink).

I also noticed that class TcpAgent has a wnd_ member variable and most
of the code uses the member function window() to get the current window
and that window() returns the minimum of wnd_ and cwnd_.

Can I add a window_ member variable to the tcp header and at the
receiver (TcpAgent::recv()) just set wnd_=tcph->window_ ?  Would this do
the job? Does anyone have a ready-made solution?

Thanks,
-- Nimrod.