Windstream provides an Optical Networking Terminal with their service. They implied that I also needed an “interface” (which is simply a router) which they would rent to the customer.
When my installer got finished installing the fiber, he wanted to hook up the “interface,’ but I took an ethernet connection directly from the ONT to a laptop that I had ready and the data connection was fine. Didn’t need that “interface” (router) at all.
When I did that, I used an old piece of CAT5 cable and the speed of the connection was right at the 300 MB/s level that I paid for.
CAT5 will work just fine (unless you require crazy-fast speeds), but you can also install a router right at your ONT and go wireless for everything in the house.
Mine is probably an outlier: it started out as a subsidiary of the municipal power utility when they recognized that running a fiber drop to every meter in order to implement energy deregulation (remember that?) created a lot of empty bandwidth, which they farmed out to multiple ISPs. At any rate, I never got a modem or router directly from them: I got my current modem (Arris CM8200) and router (TP-Link Deco) on my own.
I would think too, that CAT5 would work fine in a small house. The longest runs between nodes would likely be in the order of 50 feet, whereas the ethernet standards allow for 300 foot runs. And as DPRK points out, it’s likely Cat5e. A symptom of pushing the limits is really slow service, since there would be constant errors and retries behind the scenes.
This is generally a Bad Idea™️. By not using a router, you are putting your laptop directly on the internet. Consumer routers have both firewalls and provide Network Address Translation (NAT) which provide significant security benefits.