I want users which are connected to UAC not time out up to 8 hours means they dont need to sign in again. So I increased the heart beat interval on role to 8 hours. But my question is that should I also need to increase the session time out on firewall as well?
You should not set the interval to 8 hours. This is the heartbeat that the IC looks for from the client to see if it is still on the network. You should drop that down to somethin like 30 minutes or 1 hour. Your Session length should be set to 8 hours.