For a number of years, the MÄK RTI has supported a useful feature called FDD (or FED if we’re talking about HLA 1.3) file distribution. The original idea was that often during federation development you might find the need to update your FDD file. This often meant going around to every machine you were using and updating the local copy of the file. Obviously, this is both tedious and error prone. With FDD file distribution, only the federate that created the federation execution needed to have a local copy. When the federation was created, the file was distributed through the RTI to the rtiexec, which then distributed it to every other joining federate. This guaranteed that everyone was using the most up to date file and there were no discrepancies. There was one obvious downside to this feature however: start-up times were slower.