As strange as it may appear nowadays, there used to exist (and even still exist nowadays!) a digital transmission channel that largely predates internet. It was called the telegraph. Oh, glorious times!
In any case it was confronted with the same basic problems that can happen on a network link, i.e. loss of data, because it was a network link. So some clever mathematicians devised some clever - but highly impractical for the time since it involved doing a lot of computation - algorithms to transmit redundant information, allowing the operators to correct the data. I don't think it was much used though, most of the work was theoretical and did not necessarily involve practical implementation. You can read relevant works from Fourrier, Euler and others, or even Gallois (a stupid 20 year old kid that decided to spend the night before the duel that would take its live writing a mathematical thesis where all the foundations for - among other things - modern error correction algorithm were already present, almost 200 years ago).
You can also read relevant work from Turing and Shannon, that formalised the domain and presented practical algorithms for the then appearing "computing machines", before the 1950s.
Just to say that redundancy, error correction codes, and all that, are nothing new.
By the way, did you know that IP and TCP - the protocols used to incorporate your internet data - did not incorporate error correction mecanisms, because it was already considered a trivial problem at the time, that could easily be handled by the measly "transport" layer of the network protocol?
Well, Virgin is in charge of that "transport layer" between "the internet" and your home, I have no idea what protocol they use for that and frankly, it is none of my concern.
What is my concern is that they do corrupt the data I am downloading from the internet, data that was obviously corrupted by their transport layer, or maybe their "super winderful hub"; so obviously they do not fulfill their basic obligations as an ISP.
They have to solve that problem soon, because otherwise I am afraid they risk losing their licence if the relevant authorities become aware of the current situation. They wouldn't want to suddenly lose that wonderful source of money, and have to pay millions in compensation?
Regarding that C program... I was not pretending to provide an efficient, useful or even usable solution to a problem that Virgin still refuse to acknowledge. This is a "Virgin" support forum, they are supposed to be the ones providing the support, remember? I hope that this "rosetta stone" algorithm will nonetheless please them, and not exceed their level of mathematical knowledge. If they wish (and have the time), they can incorporate it in a nice shiny tool that they can then provide to the "very few" users affected by this issue.
You are probably right about your 2% though :-)
And btw, I used this program successfully to upgrade my linux distribution yesterday, so not a total waste of time!
