Miyoung Kang

Formal Modeling and Verification of SDN-OpenFlow

Software-Defined Networking (SDN) is a network architecture where a controller manages flow control to enable intelligent networking. Currently, a popular specification for creating an SDN is an open standard called OpenFlow. The behavior of the SDN OpenFlow (SDN-OF) is critical to the safety of the network system and its correctness must be proven so as to avoid system failures. In this paper, we report our experience in applying formal techniques for modeling and analysis of SDN-OF. The formal model of SDN-OF is described in detail and its correctness is formalized in logical formulas based on the informal specification. The desired properties are verified over the model using VERSA and UPPAAL. Our work-in-progressinvolves the development of a model translation tool that facilitates automatic conversion of the verified model to Python for modular code synthesis on the application platform

Verification for NFV-enabled network services

Network Functions Virtualization (NFV) offers a new way to design, deploy and manage network services. NFV relocates network functions from dedicated hardware appliances to generic servers, so they can run in software. Also, it is designed to consolidate and deliver the network components needed to support a virtualized infrastructure including virtual servers and storage, as well as networks. However, incomplete or inconsistent configuration of virtualized network functions (VNF) and forwarding graph (FG, aka service chain) could cause breakdown of the supporting infrastructure. Moreover, automation of NFV process with integration of Software-Defined Networking (SDN) technologies may lead the network services to be more error-prone. Recognizing these problems, we need to identify key properties to be checked. In this article, we present a framework of verification for NFV-enabled network services. Its goal is to provide a formal method for the network services that can be used to build and verify NFV components. Overall, this method makes it safer and more reliable for network operators to compose their network services in NFV environment, so that they can be assured that the properties are correctly enforced.

Process Algebraic Specification of Software Defined Networks

In this paper, we first present a formal specification for a part of Software Defined Networks(SDN) using a process algebra called Algebra of Communicating Shard Resources(ACSR). To provide a correct and efficient solution for forwarding packets on the Software Defined Networks, ACSR can express processes running concurrently and communicating switches and a controller. Forwarding packets can be modeled as prioritized synchronization of events in ACSR. During specifying formally, we could find the Subtle Ambiguity in the SDN specification. The central contribution of this paper is to describe how to apply a formal specification method to a part of informal SDN specification. It is important to specify SDN and verify the properties of the SDN using formal specification before implementing the systems. Furthermore, we prove the correctness of ACSR specification to show deadlockfreeness using VERSA.

The research on vulnerability analysis in OpenADR for smart grid

Smart Grid has become more important for the efficient use of electric power and the demand reduction. As demand for electric power is increasing continuously despite its limited capacity. The demand reduction in Smart Grid can be achieved through DR (Demand Response) which reduces demand for electric power. In this paper, we analyzed the weaknesses of open source of Open ADR, protocol for Smart Grid DR, using CERT Java secure coding rules. We extracted the violations of rules such as OBJ01-J that means the scope of declaring member variables which should be obeyed in Object-Oriented Programming and IDS00-J that means the validation for input data which should be obeyed in Web environment. By eliminating the weaknesses we could enhance the security of Smart Grid communications.

Formal specifications for software-defined networking

It is important to understand the correct specification of SDN in order to implement and analyze the SDN in mind. However, natural languages are usually ambiguous and misleading the specification due to the nature of natural language understanding. Hence, it has been required to have formal specifications after natural language documents. We have two formal specifications for a part of SDN, and compare the formalisms, called ACSR and Z.