In these experiments we test four different attack scenarios:
  1. Constant rate attack - The maximum rate is achieved immediately and maintained until the attack is stopped.
  2. Pulsing attack - The attack rate oscillates between the maximum rate and zero. The duration of active and inactive period is the same - 100 seconds.
  3. Increasing rate attack - The maximum rate is achieved gradually over 300 seconds and is maintained until the attack is stopped.
  4. Gradual pulse attack - The maximum rate is achieved gradually over 300 seconds, maintained for 20 seconds, and then gradually decreased to zero over 10 seconds. The inactive period lasts for 40 seconds and then the attack starts again.
Each scenario is tested over different runs with maximum attack rate varying from 100KBps to 2MBps. During each run legitimate traffic is interleaved with the attack traffic in the following fashion: The attack is performed through UDP packets, fixed length of 1KB. Source address is spoofed using addresses from same subnet (prefix length is 24). Source and destination ports are randomly spoofed. Since legitimate communication is conducted through SSH protocol, all TCP traffic is legitimate and all UDP traffic is the attack traffic.

Constant rate attack

Pulsing attack

Increasing rate attack

Gradual pulse attack