tcpwindowswindows-xp
Is it possible to query the current size (or some kind of graph of the buffer-size over time for that matter) of the TCP buffer of a connection?
Each endpoint of a TCP connection will have a buffer for storing data that is transmitted
over the network before the application is ready to read the data. source
But as we do not know the round-trip-time of our users
Then what's the point in trying to measure another part of the equation?
(read the man pages for lsof (-T flag) also netstat).
But trust me, the TCP system is quite smart - and the guys who wrote it are smarter than both you and I - and know a lot more about this stuff. The only thing to be concerned about is the window-scaling (these days should be disabled by default) although unless you are transferring very large files across a very high speed WAN you probably don't need it - if the files are not huge, or the bandwidth is low, then there's no beneift over using the default scale.
Best Answer
The window size in the TCP header reflects the size of the remaining buffer on each end. You can graph this using Wireshark to both capture and analyze traffic (This isn't real time, but is usually how this sort of thing is done). Choose Custom IO Graph under Statistics and do something like the following (You need to choose Advanced for the Y-Axis):
The above graphs the window size for all packets where the source address in the packet is 10.7.0.127.