The sluice package is currently available in PPA:colin-king/white and is built for Ubuntu Trusty, Utopic and Vivid, but there the git repository and tarballs are available too if one wants to build this from source.
The following starts a netcat 'server' to send largefile at a rate of 1MB a second using 1K buffers and reports the transfer stats to stderr with the -v verbose mode enabled:
cat largefile | sluice -r 1MB -i 1K -v | nc -l 127.0.0.1 1234
Sluice also allows one to adjust the read/write buffer sizes dynamically to try to avoid buffer underflow or overflows while trying to match the specified transfer rate.
Sluice can be used as a data sink on the receiving side and also has an option to throw the data away if one just wants to stream data and test the data link rates, e.g., get data from somehost.com on port 1234 and throw it away at 2MB a second:
nc somehost.com 1234 | sluice -d -r 2MB -i 8K
And finally, sluice as a "tee" mode, where data is copied to stdout and to a specified output file using the -t option.
For more details, refer to the sluice project page.