Which one? Or WISP's in general? I use my own, with my WISP. Some might not allow that. Probably depends on the WISP or type of antenna they recommend.
Most WISP's install a Mikrotik to manage the link.
You are welcome to install your own device infront of that. If you pay a little extra you might be able to get a /29 public IP and then you have a un-natted connection