Due to the limited IPv4 address space down to the number of devices currently on the internet, we need to reserve space for IPv4 addresses. Because of this, brsk and other ISPs have implemented a technology called CGNAT which allows multiple users to be behind the same public IPv4 address reserving address space.
How Does this Affect Me As A Customer:
For day-to-day internet usage, this will be fine, music/video streaming and browsing websites will all work as normal. If you want to port forward this will not be possible through CGNAT.
Why Doesn't Port Forwarding Work With CGNAT:
With a public (non-CGNAT) IPv4 normally you can change your port forwarding settings on your router to expose a service on one of your devices to the internet. For example, forwarding port 25565 (Minecraft Server) would tell the router that any incoming connections to that port would go to the specified device. However, due to the nature of CGNAT if you port forward this will not be passed through to your router.
Solution For Those Who Want/Need Port Forwarding:
Brsk offers a service called Better IP which is a static IPv4 address that is publicly routable meaning this can be used for port forwarding and is unique to you while you have the service. Looking at this in a bit more detail, with Better IP your router gets assigned a static IP address directly meaning the router will be able to listen out for these requests and know where to forward them within your network based on your port forwarding rules. However, behind CGNAT the router is unable to do this due to the extra layer of NAT added within the brsk network where the router does not get the external IP directly, therefore, it is unable to listen for incoming requests.