What is this error message problem regarding network+ settings - the 4th option when I can't be reached?

[WPCentral Question]

problem regarding network+ settings - the 4th option when I can't be reached

problem regarding network+ settings - the 4th option when I can't be reached, I found a number that I don't know, so I changed it to 0000 and then I the service was discounted and since then I can't connect to my 3G network.