It'd be nice if the Getting Started link on the n0des page went here instead of immediately asking me to sign up before I know what the hell I'm signing up for
Dumbpipe is using our set of relays. It is meant as a standalone tool as well as a showcase for what you can do with iroh.
If you use iroh as a library, you can specify your own relays.
It is important to mention that relays are interoperable, so you don't have isolated bubbles of nodes using certain relay networks. I can have the n0 relays specified and still talk to another node that is using a different set of relays.