CE25 - Réseaux de communication multi-usages, infrastructures de hautes performances, sciences et technologies logicielles

Towards effIcient bloCkchain-based disTributed SDN ArchiteCtures – TIC-TAC-SDN

To achieve the project objectives that have been introduced in Section I.2, two scientific Work Packages (WP1 & WP2) have been defined, as summarized below:

WP1 – Formal definition of the trade-off problem
Before investigating and proposing any new consensus protocol, it is needed to methodologically and thoroughly study and understand how a given blockchain technology (or family of technologies) impacts on the end-to-end dSDN application performance in order to accurately formalize the trade-off optimization problem addressed in TIC-TAC-SDN. To achieve this, two tasks are defined in WP1, namely: (i) Task 1.1 that aims to develop appropriate Design of Experiments (DoE) in order to identify influencing parameters and interactions considering the architecture as a whole (i.e., considering different types of blockchain technologies/consensus protocols, network topologies, App settings, etc.); and (ii) Task 1.2 that aims to accurately formalize the fitness (optimization) function underpinning the trade-off challenge. To put it another way, a set of blockchain technologies are considered as “black-box” models in T1.1, while T1.2 focuses on studying – for one or a subset of blockchain technologies – the underlying consensus protocol in “white-box” fashion in order to accurately formalize it, which will further help us to formalize the trade-off optimization function. These two tasks are further detailed below.

WP2 – Formal design of a new adaptive consensus protocol:
At this stage, the trade-off optimization problem is formalized, research assumptions RA1 and RA2 verified, and the blockchain-based dSDN platform is available for the coming experiment in WP2. The next step consists now to investigate, formalize, design, implement and verify innovative and smart solutions that enable the dSDN architecture to self-adapt depending on the network conditions and application-specific needs. This corresponds to the “intelligence” that is going to be embedded into the cybernetics’ reconfiguration component. To achieve this, two tasks are defined, namely Task 2.1 that aims to formally design, implement, verify and evaluate a new type of consensus protocol that has the ability to self-adapt, in a real-time and continuous fashion, in order to best meet the fitness optimization function formalized in T1.2; and (ii) Task 2.2 that aims to improve the initial version of the proposed consensus protocol with predictive analytics capabilities. In T2.2, TIC-TAC-SDN aims to explore and develop algorithms to continuously monitor/measure the system convergence time (via South-bound APIs), while taking into consideration network manager needs/expectations (via North-bound APIs) in the view to on-line optimize the fitness function. The goal is to move the towards the co-called Intelligence Defined Network (IDN) paradigm, which aims to apply ML to automatically learn and improve from experience to anticipate network-behavioural patterns/needs.

The first scientific contribution of project is related to the work done by the PI with the recruited MSc student, Matthieu Renard. It gave rise to the following outcome so far
- 1 journal article submitted to Expert Systems with Applications (IF: 8.66), which is now at the 3rd round of review (waiting for result). The submitted article, along with the feedback from reviewers are attached at the end of this document;
- 1 decision-making tool made publicly available online has been released at the following URL: credodlt.sylvainkubler.fr. This tool, which is called CREDO-DLT standing for «multiCRiteria-basEd ranking Of Distributed Ledger Technology platforms« is developed to help decision-maker to select the most suitable DLT platform alternative (i.e., that best suits their needs and requirements). A use case scenario in the context of energy communities is developed in the article to show the practicality of CREDO-DLT (cf., manuscript attached to the report).

After this first contribution, the goal is to start specifying the self-adaptive consensus protocol with the PhD student

- 1 journal article submitted to Expert Systems with Applications (IF: 8.66), which is now at the 3rd round of review (waiting for result). The submitted article, along with the feedback from reviewers are attached at the end of this document;

Submission summary

Software Defined Networking (SDN) and Blockchain are two emerging paradigms in the Internet of Things (IoT). The former greatly simplifies network programmability, the latter provides powerful tamper-proof logging and auditing capabilities that help to solve problems facing distributed SDN (dSDN) such as trust and state consistency issues among SDN controllers. Today’s literature has shown that blockchain technologies can introduce significant latency (>100sec), which is clearly inappropriate for time-critical applications. This may become all the more critical in IoT ecosystems in which hundreds to thousands of SDN controllers/apps need to cooperate/interact with one another. TIC-TAC-SDN is committed to study, design and validate a new blockchain consensus protocol that has the ability to self-adapt to find the best trade-off between reducing the system time convergence, without compromising its scalability and security, and without violating the application Service Level Agreements.

Project coordination

Sylvain Kubler (Centre de recherche en automatique de Nancy (CRAN))

The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.


UMR 7039 Centre de recherche en automatique de Nancy (CRAN)

Help of the ANR 167,011 euros
Beginning and duration of the scientific project: February 2021 - 42 Months

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