I believe 255 is the default priority (once QOS is enabled) since the router will assume all other traffic is less important? Is that correct?
If so, then no other rules are required.
Pretty sure this is correct since I'm having no problems.
I have H.323 (port 1720) set to 1, xbox 360 set to 4, ftp (ports 20,21) set to 8, https (port 443) set to 16, http (port 80) set to 128, pop3 (port 110) set to 192, and smtp (port 25) set to 224.
Everything else is 255 if my statement above is correct. Works great!