Networks are essential components for the transfer of data; therefore, advances in this area have many potential applications. Technology advances in order to facilitiate our data needs, achieving data stored in “clouds”, or to have “remote access” to data banks, seems like everyday actions. However, the complex and rigid network structure designs are still a limitation, especially for applications that require a high bandwidth, or to do maintenance and repairs. That’s where Software defined networks, or SDN, contribute to facilitate network administration, achieving through new protocols more systems flexibility.
Roberto Barros, under the direction of Dr. Sergio Sobarzo, presented his title defense Wednesday, 12 June, where he proposed the design of a series of laboratories to display these topics to students of Civil Engineering in telecommunications, detailing the use of OpenFlow software and SDN architecture. “The advantage of these devices is that a user can manipulate the network needs you may have. For example, the bandwidth of the network can de adjusted according to the amount of traffic from the nodes” said the author of the thesis “OpenFlow, teaching topics of data networks”, approved with a 6.8 by the Examining Committee.
“The advantage of these new networks is that they allow us a flexibilization of the use of the network by the operators. Thus, we are not tied to what is offered by a particular hardware manufacturer; they give us the tools to define how to conduct the network and to build countless services on it ,” indicated Professor Sobarzo, who also supervises the work of Carlos Amigo, a student who presented an example of applications of these systems in his thesis “Handover implementation for mobile clients in Wi-Fi networks defined by software/OpenFlow,” which he defended on Thursday, 13 June.
One of the problems in the networks detected by Carlos Amigo, member of the Optoelectronics division, was that with manufacturers who made the switches, such as Cisco, the communication protocols are determined by them and generally may not be handled. “For example, whoever is in charge of the network must configure each device, one by one. Then, what we did was to centralize the management, and to outsource the software, allowing you to manipulate all network devices from a single point, with a single code, which makes it easier for a network administrator,” the now telecommunications engineer explained.
With this work, a system was developed that allows to apply, in a dynamic way, various policies of traffic in a wireless software defined network (SDN). That is, these traffic rules would apply or not depending on certain events that occur on the network. Specifically, in the work advocated by Amigo, these rules focused on the handover process of a mobile client, so that this process is as smooth as possible and with the least amount of information lost. This work was approved with a maximum grade.
There are three policies addressing the handover implemented in this work: the first deals with the handover as it is in any current device, simply realizing that the client has changed position, it diverts traffic to it.
The second implementation deals with the handover in a proactive manner, i.e. decisions thinking of a possible future transfer of the mobile client. The final one consists of an arrangement of the mobile client that allows you to receive information by two interfaces simultaneously and that are working together to reduce losses, both in the handover process as in wireless communication in general.