Is DIRECTWAY an ISP or a router? Hmm. I googled and it seems it's a satellite internet provider. That means it's more or less both an ISP and router, with the potential problems of each.
As a router, there's probably a problem with the number of connections that are being opened, or the rate at which they are being opened. First, check if there are updates for the firmware in your hardware. Also, in aMule's preferences you can reduce the Max. Connections (in "Connection") and the Max. new connections / 5 secs (in "Core Tweaks"). You should also experiment with reducing your upload bandwidth limit.
As an ISP, there may be policies (open or secret) against using your connection for P2P file sharing. Try changing the port numbers that aMule is using. However, they may be analyzing you traffic or your bandwidth usage rather than relying on the port numbers. Your only choice in this case is to complain or vote with your wallet.