Upgrading: The oldqueue trick

You can hang on to ALTQ in OpenBSD 5.5 by one edit to your configuration. LIMITED TIME ONLY! WILL GO AWAY IN OpenBSD 5.6!

Simply search and replace queue -> oldqueue, so

altq on $ext_if cbq bandwidth 640Kb queue { def, ftp, udp, \
    http, ssh, icmp }
    queue def bandwidth 18% cbq(default borrow red)
    queue ftp bandwidth 10% cbq(borrow red)
    queue udp bandwidth 30% cbq(borrow red)
    queue http bandwidth 20% cbq(borrow red)
    queue ssh bandwidth 20% cbq(borrow red) { ssh_interactive, \
          ssh_bulk }
          queue ssh_interactive priority 7 bandwidth 20%
          queue ssh_bulk priority 0 bandwidth 80%
    queue icmp bandwidth 2% cbq

becomes

altq on $ext_if cbq bandwidth 640Kb oldqueue { def, ftp, udp, \
    http, ssh, icmp }
    oldqueue def bandwidth 18% cbq(default borrow red)
    oldqueue ftp bandwidth 10% cbq(borrow red)
    oldqueue udp bandwidth 30% cbq(borrow red)
    oldqueue http bandwidth 20% cbq(borrow red)
    oldqueue ssh bandwidth 20% cbq(borrow red) { ssh_interactive, \
          ssh_bulk }
          oldqueue ssh_interactive priority 7 bandwidth 20%
          oldqueue ssh_bulk priority 0 bandwidth 80%
    oldqueue icmp bandwidth 2% cbq

But you will need to switch to new queues in time for OpenBSD 5.6. We take a little detour to the queues section of the PF tutorial.