[c-nsp] what limits bw on a tcp stream?

[Mark Boolootian]

> I have gear in Amsterdam and in San Jose.  Pushing log files from 
> Amsterdam to San Jose through rsync seems to top out at 7Mbps even 
> though the box doing the push is pushing much more out to the Internet. 
>   If I run several rsync's it goes quicker so I know I have the bandwidth.
> 
> What's limiting me?

Check out the TCP tuning guides:

  http://dsd.lbl.gov/TCP-tuning/
  http://psc.edu/networking/projects/tcptune/

Is rsync using ssh to move the data?  ssh has its own windowing
issues.  There's a high perf fix for that which you should be able
to find via google.