New cooperative mechanisms for software defined networks based on hybrid switches

Abstract

Software defined networking (SDN) aims to provide simplified network design, operation, and management using a decoupled control plane. However, its centralized control and global network knowledge present scalability and reliability issues, which makes SDN deployment very challenging. In this paper, we propose and evaluate a hybrid switch with partial delegation of basic bridging and new cooperative mechanisms between controller and switches. This delegation offloads the SDN controllers while maintaining the capability to install forwarding rules on the switches. In this way, we take full advantage of hybrid switches in addition to using them as backwards compatible equipment, which interoperates with traditional switches.We validate this proposal by implementing a hybrid OpenFlow switch on an open source software switch as a proof of concept. Scalability and path setup delay are improved with respect to traditional centralized SDN solutions, because of the reduction in controller load and, in turn, because of the reduced traffic between switches and controller. Our cooperative mechanisms focus on recovering failures, obtaining the best performance of all approaches on higher loads, and providing a good trade‐off between controller based and traditional distributed approaches.

A Hybrid SDN Switch Based on Standard P4 Code

“…Possible solutions range from running in parallel multiple synchronised controller instances as in [9], to implement controller offloading techniques such as delegating or reverting back certain control plane tasks to the data plane [3]. The latter can be accomplished by using hybrid SDN devices with autonomous forwarding capabilities that can be enabled or disabled by the control plane [4] and permits new cooperative mechanisms between the control and data plane if all hybrid SDN devices possess the same autonomous capabilities. This is a cumbersome requirement and limitation unless it comes coupled with data plane programmability features.…”

“…This is very useful if the control plane is only interested in managing premium services (due to priority level agreements or security reasons), but does not care/have resources to manage them all. Work in [4] shows that hybrid SDN switches, capable of autonomously applying self-learning forwarding rules if control plane rules do not match, alleviate the load at the control plane (since exchanged packets and processing needs are reduced).…”

“…Such data structures are used to store state information, with the aforementioned goal of enabling autonomous forwarding in the data plane without the intervention of a control plane. Unlike previous works [5], our proposal uses standard P4supported data structures, having the advantage of being fully portable and executable by any P4 target, and achieving the same level of offloading of the control plane tasks as other hybrid SDN devices [4]. Moreover, it makes the deployment in networks with heterogeneous P4 devices easier.…”

A systematic literature review on formal verification of software‐defined networks

“…SDN is a new architecture that navigates the application plan on control plan for transferring data plan. The primary SDN architecture comprises of existing operational processes such as resource selection and allocation, traffic arranging and accelerating, and confirmation in three main layers including, application plan layer, data plan layer, and control plan layer . The existing plans communicate with each other using related application programmable interfaces (APIs) with some existing roles .…”

Improving Multipath Routing of TCP Flows by Network Exploration

“…Apart from the fully distributed process described above, we envisage other ways to implement the path recovery process. For instance, we could leverage an SDN controller and the OpenFlow protocol to deploy a centralized path recovery mechanism or even use a hybrid approach where the controller and the switches cooperate to recover the path [28].…”