  IoT Servers that receive and process packets from IoT devices should meet the
QoS needs of incoming packets, and support Attack Detection software that
analyzes the incoming traffic to identify and discard packets that may be part
of a Cyberattack. Since UDP Flood Attacks can overwhelm IoT Servers by creating
congestion that paralyzes their operation and limits their ability to conduct
timely Attack Detection, this paper proposes and evaluates a simple
architecture to protect a Server that is connected to a Local Area Network,
using a Quasi Deterministic Transmission Policy Forwarder (SQF) at its input
port. This Forwarder shapes the incoming traffic, sends it to the Server in a
manner which does not modify the overall delay of the packets, and avoids
congestion inside the Server. The relevant theoretical background is briefly
reviewed, and measurements during a UDP Flood Attack are provided to compare
the Server performance, with and without the Forwarder. It is seen that during
a UDP Flood Attack, the Forwarder protects the Server from congestion allowing
it to effectively identify Attack Packets. On the other hand, the resulting
Forwarder congestion can also be eliminated at the Forwarder with "drop"
commands generated by the Forwarder itself, or sent by the Server to the
Forwarder.
