[ns] TCP Receiver/Sink Advertised Window

[Brian Lee Bowers <bowersb@lanl.gov>]

Two suggestions (I'll work on patches this afternoon):

1)	make Maximum Window Size (MWS) a data member of TCPSink.  This 
would allow tuning MWS for each inidividual sink object.  As it is, 
all sinks have the same MWS (1024).

2)	allow source and sink to negotiate the receive window size.  The 
sink knows (or could know) how many packets it can buffer, so why not 
share this information with the source.  This would require a full 
three-way handshake (or perhaps only a two-way handshake, as is 
already implemented for New Reno?).

This came up because I was running a sim that allowed the source to 
send massive amounts of data (8192 packets of 1500 bytes each).  In 
the most recent run, the source needlessly retransmitted over 560 
packets.  MWS, #define'd to be 1024, was too small to absorb the 
number of packets outstanding for the source.  After much hunting in 
the source for TCPSink, I found a MACRO variable, MWM, which was 
#define'd as MWS - 1.

-- 
Brian Lee Bowers	|	RADIANT Team (Summer Intern)
bowersb@lanl.gov	|	Los Alamos National Laboratory