I want to setup QoS on my DD-WRT router. I found this wiki page, but what puzzles me is that it needs to know my WAN bandwidth.
"Set your download and upload speeds. You can use a speed test like Speedtest.net to check your actual connection speed. Some ISPs also provide their own bandwidth testing service, which may be more reliable than the links provided. Enter no higher than 95% of the values you measured into the proper fields."
I don't want to provide my bandwidth because my bandwidth may change depending on my ISP, which is not always fixed.
What I want to do is to give my VoIP phone the highest priority. That means every packet to and from the IP (or its interface) is allowed to jump to the head of the queue.
Why does the router need to know my bandwidth?