Why OpenBSD? Traffic shaping

The new queue and priorities system replaced 15 year experiment ALTQ in OpenBSD 5.5:

queue rootq on $ext_if bandwidth $ext_bw

queue main parent rootq bandwidth 20479K min 1M max 20479K qlimit 100

queue qdef parent main bandwidth 9600K min 8000K max 18M default

queue qweb parent main bandwidth 9600K min 8000K max 18M

queue qpri parent main bandwidth 2000K min 700K max 2500K burst 4000K for 3000ms

queue qdns parent main bandwidth 100K min 12K burst 600K for 3000ms

queue spamd parent rootq bandwidth 1K min 0K max 1K qlimit 300

Tie into PF rules with match or pass