The Research Of Openflow Protocol Testing Techniques

OpenFlow is a new network protocol. Its core idea is separating the control ability and forwarding ability in tranditional routers and this operation should be implemented by software. OpenFlow is the first standard communication interface protocol between control plane and data plane in SDN structure. It’s aimed at the biggest weakness of traditional network-controllability, so soon as launched it has received widespread attention and support and has played a huge role in promoting innovation and development of network. However, since OpenFlow is a new protocol, different vendors may has different understanding on it and may also has different implementation. In this case, OpenFlow protocol testing techniques becomes more important.Network protocol testing includes functional testing and performance testing. It consists of conformance testing, performance testing, interoperability testing and robustness testing, while conformance testing is the foundation of other testing techniques and the soul of total protocol testing. Protocol conformance testing is the process of testing protocol implementations based on the standardized description of the protocol, so as to determine whether the protocol implementation is consistent with the protocol specification.To specify the protocol conformance testing requirements and methods, the International Organization for Standardization specially released a set of international standards--ISO/IEC9646(OSI conformance testing methodology and framework) in1994. In1997, the Chinese Ministry of Electronics Industry released the Chinese version of the standard, namely GB/T17178. It clearly specified the protocol conformance testing methods. Although the GB/T17178is mainly for the OSI protocol conformance testing,the general requirements and objectives of protocol conformance testing specified in it is widely applicable, and could serve as an important guidance to OpenFlow conformance testing.This paper mainly did the following researches:1. Combining with the characteristics of OpenFlow, we proposed a structured OpenFlow conformance testing methodology based on GB/T17178standard. We divides a complete OpenFlow test suite into several different test cases, which cover basic interconnection tests group and capability&behavior tests group. Referenced to test cases in OFTest, we proposed a hierarchical OpenFlow conformance testing methodology. With the test objectives and test cases structured, we can make test design more comprehensive, covering every points that should be tested. This also makes expansion of test cases more convenient.2. By calling the test methods already contained in OFTest directly or encapsulating new test methods by APIs supported by OFTest, we did conformance testing on OpenFlow switch and analyzed typical test cases.