70 4 Software-Defined Networks Principles and Applications
Centralized control plane
Data plane network
Northbound open API
Applications
Figure 4.1 SDN architecture.
Controller
Virtualization
FlowVisor
FlowVisor
console
Applications
LAVI
Broadcom
Ref. Switch
NetFPGA
OpenFlow
switches
Monitoring tools
Open vSwitch
HP, IBM, NEC,
Pronto, Juniper..
and many more
PCEngine
WiFi AP
OpenWRT
Software
Ref. Switch
...
...
FloodLight
n-Casting
ENVI (GUI)
openseer
oflops
oftrace
Trema
Beacon
NOX
Figure 4.2 SDN components and examples.
which the control plane software is distributed across all the data
plane devices in the network. Figure 4.3 shows the transition from
today’s integrated box view to the separation view. In this design, the
centralized control enables deployment of new services and applications that are not possible or are very difficult in traditional distributed
networks. The deployment of new services is much faster compared to
upgrading a whole networking device as it is done by current vendors.
The separation of control and data planes enables independent and
parallel optimizations of the two planes. We envision that this path