It is mostly experienced by broadband users that run networks/routers where Network Address Translation is employed. If I receive a file it is fine, if I try to send it disconnects my IRC connection though the connection to the 'net itself remains fine.
There's a few ways around it but each one involves making the LAN more open to exploitation by hackers, something that I am not prepared to do just for the sake of sending files which can be emailed or uploaded to my website for distribution.
Distribution from a website is the best option because the user can get the download at a time of their choice and if you are intending to give the file to any people it is also cheaper. In the Australian experience there is no reputable long-standing companies providing unlimited bandwidth for brodband these days, even though there are a few small niche providers experimenting with re-introduction of the unlimited plans. Whereas I get 12GB of bandwidth from my website per annum for AU$275.00. There's no contest.
People are free to run mIRC's DCC server or open/forward ports for DCC, but as I said before, I believe that this leaves a LAN open to exploitation.
