L18

21 Novembro 2025, 16:00 • José André Moura

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The current laboratorial lecture taught how to write a Ryu application that supports scenarios with multiple SDN controllers. There are three possible functional roles for each SDN controller forming the cluster of the diverse SDN controllers. The three possible SDN controller roles are MASTER, SLAVE, or EQUAL. This lecture aims to deliver to its practitioners relevant knowledge in the next aspects: i) study the two possible switch (OVS) reactions after that switch lost the communications with the SDN controller; ii) show how each SDN controller is configured for its role within the control cluster; iii) evidence how the control cluster formed by distinct SDN controllers enhances the resiliency of the control plane against any SDN controller failure; iv) study how the SDN controllers divide among them the control responsibility of the diverse nodes of the data plane, i.e. the control channel workload; and v) study the fairness on workload share among the SDN controllers, considering diverse policies for sharing that workload among them.

L17

21 Novembro 2025, 14:30 • José André Moura

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SDN Control has a Centralized Design. Switch Actions to Address Communication Failure with the SDN Controller. Control Plane Actions to Address Failures. Multiple SDN controllers. Distributed consensus among SDN controllers. Next Laboratory.

L16

14 Novembro 2025, 16:00 • José André Moura

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The current laboratorial lecture taught how to deploy a Ryu SDN application that offers an on-demand elastic service, which is designated as the fog datacenter. The fog datacenter automatically detects the need to activate a part of the network topology before routing some traffic destined to some destination node. This destination node is also activated before the SDN application controlling the necessary switches to deploy the routing path through the network infrastructure to that receiving node. This fog datacenter could offer heterogeneous resources, such as networking, computation, and storage, where and when those resources are necessary, at the network edge.

L15

14 Novembro 2025, 14:30 • José André Moura

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OpenFlow v1.3. The relevance of programming the aimed operation of a networking infrastructure. Future X Network - A new revolution on his way. Edge Micro Datacenter: Fog Datacenter. Fog Datacenter: System Architecture. Next Laboratory.

L14

7 Novembro 2025, 16:00 • José André Moura

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The current laboratory taught how to use the Northbound Representational State Transfer (REST) Application Programming Interface (API) between a top-level application and the Ryu Controller. The top-level application is deployed as curl shell commands, which send HTTP (Hypertext Transfer Protocol) messages to the Software Defined Networking (SDN) controller REST API for managing the network topology. The network topology is emulated by Mininet. The REST API of Ryu was extended to support new functionality involving the management of Virtual LANs (VLANs) over the network topology.