Why am I getting this error?

I downloaded LoL when at college and had no connection issues what so ever, then when I bring my computer back home the game keeps telling me that I am disconnected from PVP.net. I went through the trouble shooting steps and still nothing is working. Once I am able to get into the game it is fine and no issues playing but being able to get there is a pain in the ass. Any advice on how to fix this? Thanks?