I have not heard of anyone intentionally interfering with microwave links, but generally speaking these RF lines are not reliable and you get gaps from time to

I have not heard of anyone intentionally interfering with microwave links, but generally speaking these RF lines are not reliable and you get gaps from time to time due to weather and whatnot. There are a couple of ways to deal with this. In the market data case, the data only flows in one direction and usually consists of sequenced messages, so you just send the data down both the microwave and a fiber path simultaneously. You can do simple line arbitration (throw away duplicates) at the receiving end.