Upgrading: The oldqueue trick

You can hang on to ALTQ in OpenBSD 5.5 by one edit to your configuration.

LIMITED TIME ONLY! GONE 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 (or do the rethink cold turkey).