I insisted to our ISP that we own and operate our own router: out of the blue, it attempted to add remote access without my consent during a maintenance visit. I refused as it potentially gave it access to our network devices, so the company installed its own router which we then wired into with our two routers. It gives us an added layer of protection, although of course the ISP router could still be compromised by a hacker if the company leaves open port 7547.