Using Self-Similarity to Increase Network Testing Effectiveness

2009

Network simulators, which implement network protocols under some simulated conditions, have been widely used to analyze the feasibility of network protocols. Conformance testing of the simulator against the protocol is a very important task in the community of telecommunications. However, many current conformance testing methods face a problem of finding a systematic mechanism to verify the test outputs. This paper proposes to use an innovative testing approach, metamorphic testing (MT), to alleviate such a problem. We select one ad-hoc on-demand distance vector (AODV) simulator for study and test its conformance against the AODV protocol by the MT technique. Through our experiments, we illustrate the applicability of MT in the protocol conformance testing, confirm the reliability of the selected AODV simulator, and demonstrate the cost-effectiveness of MT using the mutation analysis technique.

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The development of communications systems demands testing. This paper presents a framework for testing onthe-fly, which relies on the identification of 3 types of tests and on their sequential execution. The ioco conformance relation was adopted in order to assign verdicts.

Computer Communications, 1995

International Journal on Software Tools for Technology Transfer, 2005

In the context of computer networks, conformance testing determines whether an implementation under test conforms to its specification. Testing was carried out in a centralized and sequential way. This is no longer feasible or realistic as systems to be tested have become increasingly complex and can be widely distributed. Our further goal is to evaluate how a distributed approach can help in testing complex systems such as a network's components efficiently. We present two solutions to generate automatically distributed tests. As it is somehow less difficult to generate centralized tests, the proposed solutions consist in automatically distributing these tests. By applying these solutions to military ISDN protocols, we showed that: (i) the solutions ease development of distributed tests and (ii) distributed tests obtained are well suited for testing complex systems.

IFIP Advances in Information and Communication Technology, 1997

Formal verification techniques need to deal with the complexity of the systems being verified. Most often, this problem is solved by taking an abstract model of the system and aiming at a complete verification of an approximation of the system. This paper proposes a complementary verification approach, in which the approximation is introduced into the verification algorithm, instead of the system model: we achieve an approximate verification of a fair~y complete and detailed system model. The proposed technique relies on coupling a Genetic Algorithm with a simulator of the system under verification, and is especially suited for verifying performance-related aspects. To prove the effectiveness of our approach, we applied it to the quantitative verification of a network protocol: the TCP protocol operating on a given network. A Genetic Algorithm is able to find a configuration of the traffic over the network that sensitizes a critical problem in the TCP protocol that would be difficult to find both with exact techniques and stochastic ones.

AT&T Technical Journal, 1990

In this paper, we present a generic approach for modeling a communications protocol with state transitions and Sherlf is a member of ~dvanced Digital Signal window and timer mechanisms, and for generating con-Uyar is a member of formance test sequences automatically. Based on this model, minimum-cost (i.e., minimum run time) confor-Processing Department, and M. h i t technical staff in the Standards Deoaflment. method based On Unique input/ou@ut sequences and mance test sequences can be generated by using a Network lnterfaces and hey are with AT&T ~r. Sherif works on the Rural Chinese Postman tours. As a case study, this method is applied to the Integrated Services Digital Network link-access protocol on the D channel. Laboratories in Holmdel, New Jersey. systems engineering and standardization of wideband packet protocols. He joined AT&T Bell Laboratories in 1983 and has both a B. Sc. in electronics and communications and an M.

Bell Labs Technical Journal, 2003

Testing large-scale software applications has been an area of activity for a long time. Today several fields like design patterns advocate very good practices that aim to ease the burden of testing. However, in practice, testing is often done in an ad hoc manner. Large-scale software systems like network management systems are tested against very specific system requirements, which tend to be inadequate. Such large-scale systems, comprising concurrent multi-threaded processes interacting with each other, often need to be tested for long periods of time (sometimes longer than the time taken to develop the system) before they are suitable for deployment on a live network. Despite such stringent system requirements, testing often takes a back seat, and sophisticated software tools, though available, are very rarely employed in system testing. Here we describe an engineering approach for testing and verification of network management and design tools. We describe a set of handy principles, algorithms, and testing architectures that have worked very well in practice and have achieved remarkable results. The paper derives heavily from our experience; we have developed several products for Lucent Technologies' Optical Networks organization over the last three years.

IEEE Design and Test of Computers, 2004

2012

In the world of designing network protocols, verification is a crucial step to eliminate weaknesses and inaccuracies of effective network protocols. There are many models and tools to verify network protocols, including, Finite State Machines (FSM), Colored Petri Nets (CP-Nets), Temporal Logic, Predicate Logic, Estelle Specification, Path based Approach etc. This paper presents a survey of various techniques for verifying correctness properties of communications protocol

EPL, 2009

Motivated by widely observed examples in nature, society and software, where groups of related nodes arrive together and attach to existing networks, we consider network growth via sequential attachment of linked node groups, or graphlets. We analyze the simplest case, attachment of the three node W-graphlet, where, with probability α, we attach a peripheral node of the graphlet, and with probability (1 − α), we attach the central node. Our analytical results and simulations show that tuning α produces a wide range in degree distribution and degree assortativity, achieving assortativity values that capture a diverse set of many real-world systems. We introduce a fifteen-dimensional attribute vector derived from seven well-known network properties, which enables comprehensive comparison between any two networks. Principal Component Analysis of this attribute vector space shows a significantly larger coverage potential of real-world network properties by a simple extension of the above model when compared against a classic model of network growth.