235
© 2010 Taylor & Francis Group, LLC
11
QOs issues in
OpenFlOw/sdn
KUHELI L. HALDAR AND
DHARMA P. AGRAWAL
Introduction
e architecture of a network’s physical infrastructure significantly
affects the overall performance of the network. In today’s traditional
network system, the control and the data plane are tightly coupled into
the same hardware, as shown in Figure 11.1. However, each plane has
separate tasks that provide the overall switching/routing functional-
ity. e control plane is responsible for computing and programming
the paths of the data flows. Once these paths have been determined,
they are then sent and stored in the data plane. e typical function
of the data plane is to make path decisions in the hardware based on
the latest in