From: BoD 


This curve comes from the netfilter packet filtering HOWTO from Rusty Russell 
http://www.netfilter.org/unreliable-guides/packet-filtering-HOWTO/packet-filtering-HOWTO.linuxdoc-7.html




       rate (pkt/s)
             ^        .---.
             |       / DoS \
             |      /       \
Edge of DoS -|.....:.........\.......................
 = (limit *  |    /:          \
limit-burst) |   / :           \         .-.
             |  /  :            \       /   \
             | /   :             \     /     \
End of DoS  -|/....:..............:.../.......\..../.
 = limit     |     :              :`-'         `--'
-------------+-----+--------------+------------------> time (s)
   LOGIC =>  Match | Didn't Match |    Match