OpenBSD is pretty good by default. Traffic with different TOS is separately queued with reasonable priority defaults. So you normally don't have to do anything.

OpenBSD is pretty good by default. Traffic with different TOS is separately queued with reasonable priority defaults. So you normally don't have to do anything. I was a bit surprised that my VOIP stuff was just working when I moved my router from Linux to OpenBSD and had to go looking to figure out why.