Taixin Li

Using SDN and NFV to Implement Satellite Communication Networks

Satellite communication system suffers inefficient and inflexible management and configuration due to the traditional system design. To address this issue, in this paper, we present a space-ground integrated multi-layer satellite communication network, based on Software Defined Network and Network Function Virtualization. The framework consists of a Software Defined Network based three-layer satellite network to provide effective traffic scheduling, and a Network Function Virtualization based service deployment method to provide flexible and reconfigurable satellite services delivery. Based on the proposed framework, we implement a prototype with help of Delay Tolerant Network and OpenFlow. Then, we design an experiment scenario and conduct experiments in the prototype to validate the feasibility of the proposed framework and the functionality of the prototype.

A new method for providing network services: Service function chain

Abstract Service deployment and management have been a challenge for the network operators because of the characteristics of traditional methods for service configuration and service deployment: unchangeable configuration and ossified deployment. Based on the ideas of Service Function Chain (SFC), Network Functions Virtualization (NFV), Software Defined Network (SDN), and Path Computation Element (PCE), we introduce a method that can not only maintain the services in a flexible and scalable way, but also place services in a topology-independent way and steer traffic among different services. We abstract the service path selection problem as a grey system theory problem and propose an algorithm to give a proper service composition selection and traffic steering method. We also validate the usability of the proposed solution in prototype and efficiency of the proposed algorithm in simulation environment.

SAT-FLOW: Multi-Strategy Flow Table Management for Software Defined Satellite Networks

Software-defined satellite network (SDSN) is a novel framework, which brings software-defined network technologies in the satellite networks. It has great potential to achieve effective and flexible management in the satellite networks. There are two burning issues to be solved for the flow table management in SDSN. First, the ternary content addressable memory (TCAM) space is limited on satellites and the flow table size should be reduced. Second, the frequent handovers will lead to an increase in the flow table size in SDSN. Due to the limited flow table space, a lot of flows will be dropped if the flow table is full during the handover. To address these issues, we first give a description of our focused flow table management problems. Then, we propose <italic>SAT-FLOW</italic>, a multi-strategy flow table management method for SDSN. <italic>SAT-FLOW</italic> considers three key points, limited TCAM space, classified traffic, and handover. <italic>SAT-FLOW</italic> contains two heuristic algorithms, named dynamic classified timeout (<italic>DCT</italic>) algorithm and timeout strategy-based mobility management (<italic>TSMM</italic>) algorithm. <italic>DCT</italic> aims to reduce the flow table size and <italic>TSMM</italic> aims to reduce the drop flows during the handover. We implement <italic>SAT-FLOW</italic> and conduct contrast experiments. The experimental results verify the good performance in terms of transmission quality, <italic>idle_timeout</italic> values distribution, a 15.27%–24.34% decrease in flow table size, an 8.2%–10.4% decrease in drop-flow rate, and a 4.92%–5.7% decrease in table misses for the high priority traffic during the handover.

Fuzzy Theory Based Security Service Chaining for Sustainable Mobile-Edge Computing

Mobile-Edge Computing (MEC) is a novel and sustainable network architecture that enables energy conservation with cloud computing and network services offloading at the edge of mobile cellular networks. However, how to efficiently manage various real-time changing security functions is an essential issue which hinders the future MEC development. To address this problem, we propose a fuzzy security service chaining approach for MEC. In particular, a new architecture is designed to decouple the required security functions with the physical resources. Based on this, we present a security proxy to support compatibility to traditional security functions. Furthermore, to find the optimal order of the required security functions, we establish a fuzzy inference system (FIS) based mechanism to achieve multiple optimal objectives. Much work has been done to implement a prototype, which is used to analyze the performance by comparing with a widely used method. The results prove that the proposed FIS mechanism achieves an improved performance in terms of Inverted Generational Distance (IGD) values and execution time with respect to the compared solution.

SERvICE: A Software Defined Framework for Integrated Space-Terrestrial Satellite Communication

The existing satellite communication systems suffer from traditional design, such as slow configuration, inflexible traffic engineering, and coarse-grained Quality of Service (QoS) guarantee. To address these issues, in this paper, we propose SERvICE, a Software dEfined fRamework for Integrated spaCe-tErrestrial satellite Communication, based on Software Defined Network (SDN) and Network Function Virtualization (NFV). We first introduce the three planes of SERvICE, Management Plane, Control Plane, and Forwarding Plane. The framework is designed to achieve flexible satellite network traffic engineering and fine-grained QoS guarantee. We analyze the agility of the space component of SERvICE. Then, we give a description of the implementation of the prototype with the help of the Delay Tolerant Network (DTN) and OpenFlow. We conduct two experiments to validate the feasibility of SERvICE and the functionality of the prototype. In addition, we propose two heuristic algorithms, namely the QoS-oriented Satellite Routing (QSR) algorithm and the QoS-oriented Bandwidth Allocation (QBA) algorithm, to guarantee the QoS requirement of multiple users. The algorithms are also evaluated in the prototype. The experimental results show the efficiency of the proposed algorithms in terms of file transmission delay and transmission rate.

Modeling software defined satellite networks using queueing theory

Existing satellite communication has a low efficiency due to the inherent defects of the traditional design, i.e., coarsegrained control, and long configuration delay. In some previous work, researchers developed Software Defined Satellite Networks (SDSN). We reconsidered many characteristics equipped in satellite links, and deployed SDSN in the prototype by leveraging Delay Tolerant Network (DTN) and OpenFlow. However, it is necessary to develop a theoretical tool for this new network architecture to evaluate its performance. In this paper, we propose such an analytical model for SDSN using the queueing model. In particular, the Jacksons theorem is adopted to model the communication between a controller and forwarding nodes, and the store-and-forward process. The comparisons between the numerical and experimental results indicate that the proposed model is able to accurately evaluate the performance of SDSN, and will provide great benefits for the further related researches.

Timeout Strategy-based Mobility Management for Software Defined Satellite Networks

Software Defined Satellite Network (SDSN) is a novel framework which brings Software Defined Network (SDN) technologies in the satellite networks. It has great potential to achieve effective and flexible management in the satellite networks. However, the frequent handovers will lead to an increase in the flow table size in SDSN. Due to the limited flow table space, a lot of flows will be dropped if the flow table is full during the handover. This is a burning issue to be solved for mobility management in SDSN. In this paper, we propose a heuristic Timeout Strategy-based Mobility Management algorithm for SDSN, named TSMM. TSMM aims to reduce the drop-flows during handover by considering two key points, the limited flow table space and satellite link handover. We implement TSMM mechanism and conduct contrast experiments. The experimental results verify the good performance in terms of transmission quality, an 8.2%-9.9% decrease in drop-flow rate, and a 6.9%–11.18% decrease in flow table size during the handover.