NOTE: Blizzard does not support P2P in their game World of Warcraft as of patch 6.2.5. This issue should not be a problem if you are running the current version of World of Warcraft.

1)  From the Options menu, choose Downloader Preferences.

2)  Uncheck the box next to Enable Peer-to-Peer Transfer. Then, click OK.

Outcome

If your computer had been blocked from access to the TTUnet network, it will be able to access the network after fifteen minutes assuming no other P2P software is running on the computer.

World of Warcraft can be updated through means other than P2P file transfers.