The implied warranty of merchantability guarantees that a product sold to you will work for its intended purposes. In other words, it means you can expect a toaster to toast your bread. If it doesn't, you have legal protection against losing money on a product that doesn't work.
If you bought the router expecting it to work as advertised, you may make a claim if it doesn't. They would have to spell out ahead of time what the limitations and requirements are in order to avoid trouble.