In present days there is more emphasis on how a Content Delivery Network (CDN) can optimally handle the traffic flowing through it. The Application-Layer Traffic Optimization (ALTO) protocol is one of the solutions of this endless issue. This newly developed traffic-optimization protocol optimizes the dataflow not on the real time traffic information basis but using the earlier collected network- and cost maps from the network or content providers. Furthermore the ALTO gives recommendation instead of strict rules based on the available information to achieve the optimal state.
In my thesis I implemented and made simulations with the ALTO service over a Software Defined Networking (SDN). To build up the environment I had to modify an SDN controller to be capable to provide ALTO services. Furthermore the ALTO gives only recommendations hence implementation of a flow redirect mechanism was needed in the controller. The result of the work is a system which gives recommendation to the optimal routes based on the given information to reach some kind of content in the network. The recommendation is validated and activated by the redirecting mechanism.