Publicado em: 24/08/2015

Dissertação de Mestrado – Tobias Brignol Petry

UNIVERSIDADE FEDERAL DO RIO GRANDE DO SUL
INSTITUTO DE INFORMÁTICA
PROGRAMA DE POS-GRADUAÇÃO EM COMPUTAÇÃO

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DEFESA DE DISSERTAÇÃO DE MESTRADO

Aluno: Tobias Brignol Petry
Orientador: Prof. Dr. Antonio Marinho Pilla Barcellos
Título: Avoiding Control Plane Partition in Software Defined Networks through Cellular Networks: assessing opportunities and limitations
Linha de Pesquisa: Redes de computadores
Data: 24/08/2015
Hora: 9:30
Local: Prédio 43412 – Sala 218 – Sala de videoconferência, Instituto de Informática.

Banca Examinadora:
Prof. Dr. Magnos Martinello (UFES – por videoconferência)
Prof. Dr. Cesar Augusto Fonticielha de Rose (PUCRS)
Prof. Dr. Lisandro Zambenedetti Granville (UFRGS)
Presidente da Banca: Prof. Dr. Antonio Marinho Pilla Barcellos

Abstract: Software Defined Networks simplify network programmability by detaching the control plane from forwarding devices and deploying it into a logically centralized controller. While this allows a clearer separation of concerns, it also creates a dependency between them. Failures in the control plane break the controller view of the network state and could render the network unusable if forwarding devices cannot be reached. The relevance of this problem has led to a range of proposals, including physical distribution of controller instances and delegation of concerns to forwarding devices. This dissertation features the proposal and evaluation of an architecture that leverages cellular data networks (4G) as control plane backup links. No previous work has explored this idea, despite the recent research intersecting SDN and wireless networks. The experimental evaluation provides insights towards answering three research questions: (i) How is the behavior of control plane traffic affected by the characteristics of cellular links, (ii) how quickly is the control plane handed over to the backup link when a failure occurs and (iii) how well do network functions that rely on a snapshot of the network state behave on such an architecture. Despite the expected higher latency of cellular links, this architecture maintains partial functionality of tasks that depend on global network awareness when failures occur in primary control links in a simple, affordable fashion. The degree to which the functionality of these tasks is maintained is directly related to its dependency on the timeliness of control plane reaction to network events. The main benefit of preventing control plane partition is to maintain a consistent global view of the network.