Software Defined Networking(SDN)is programmable by separation of forwarding control through the centralization of the controller.The controller plays the role of the‘brain’that dictates the intelligent part of SDN t...Software Defined Networking(SDN)is programmable by separation of forwarding control through the centralization of the controller.The controller plays the role of the‘brain’that dictates the intelligent part of SDN technology.Various versions of SDN controllers exist as a response to the diverse demands and functions expected of them.There are several SDN controllers available in the open market besides a large number of commercial controllers;some are developed tomeet carrier-grade service levels and one of the recent trends in open-source SDN controllers is the Open Network Operating System(ONOS).This paper presents a comparative study between open source SDN controllers,which are known as Network Controller Platform(NOX),Python-based Network Controller(POX),component-based SDN framework(Ryu),Java-based OpenFlow controller(Floodlight),OpenDayLight(ODL)and ONOS.The discussion is further extended into ONOS architecture,as well as,the evolution of ONOS controllers.This article will review use cases based on ONOS controllers in several application deployments.Moreover,the opportunities and challenges of open source SDN controllers will be discussed,exploring carriergrade ONOS for future real-world deployments,ONOS unique features and identifying the suitable choice of SDN controller for service providers.In addition,we attempt to provide answers to several critical questions relating to the implications of the open-source nature of SDN controllers regarding vendor lock-in,interoperability,and standards compliance,Similarly,real-world use cases of organizations using open-source SDN are highlighted and how the open-source community contributes to the development of SDN controllers.Furthermore,challenges faced by open-source projects,and considerations when choosing an open-source SDN controller are underscored.Then the role of Artificial Intelligence(AI)and Machine Learning(ML)in the evolution of open-source SDN controllers in light of recent research is indicated.In addition,the challenges and limitations associated with deploying open-source SDN controllers in production networks,how can they be mitigated,and finally how opensource SDN controllers handle network security and ensure that network configurations and policies are robust and resilient are presented.Potential opportunities and challenges for future Open SDN deployment are outlined to conclude the article.展开更多
In order to manage all kinds of network security devices and software systems efficiently, and make them collaborate with each other, the model for an open network security management platform is presented. The feasib...In order to manage all kinds of network security devices and software systems efficiently, and make them collaborate with each other, the model for an open network security management platform is presented. The feasibility and key implementing technology of the model are expatiated. A prototype system is implemented to validate it.展开更多
Due to 5G's stringent and uncertainty traffic requirements,open ecosystem would be one inevitable way to develop 5G.On the other hand,GPP based mobile communication becomes appealing recently attributed to its str...Due to 5G's stringent and uncertainty traffic requirements,open ecosystem would be one inevitable way to develop 5G.On the other hand,GPP based mobile communication becomes appealing recently attributed to its striking advantage in flexibility and re-configurability.In this paper,both the advantages and challenges of GPP platform are detailed analyzed.Furthermore,both GPP based software and hardware architectures for open 5G are presented and the performances of real-time signal processing and power consumption are also evaluated.The evaluation results indicate that turbo and power consumption may be another challengeable problem should be further solved to meet the requirements of realistic deployments.展开更多
There are an increasing of scenarios that require the independent bandwidth and delay demands. For instance, in a data center, the interactive message would not occupy much bandwidth, but it requires the rigorous dema...There are an increasing of scenarios that require the independent bandwidth and delay demands. For instance, in a data center, the interactive message would not occupy much bandwidth, but it requires the rigorous demands for the delay. However, the existing QoS approaches are mainly bandwidth based, which are inappropriate for these scenarios. Hence, we propose the decoupled scheme in the OpenFlow networks to provide the centralized differential bandwidth and delay control. We leverage the mature HTB to manage the bandwidth. And we design the Queue Delay Management Scheme (QDMS) for queuing delay arrangement, as well as the Comprehensive Parameters based Dijkstra Route algorithm (CPDR) for the propagation delay control. The evaluation results verify the decoupling effectiveness. And the decoupled scheme can reduce the delay for high priority flows.展开更多
In this paper, the open queueing network model is proposed for solving the problem of public transportation in cities. The vertices of the networks(i.e., the bus stops) are determined by means of the fuzzy clusteri...In this paper, the open queueing network model is proposed for solving the problem of public transportation in cities. The vertices of the networks(i.e., the bus stops) are determined by means of the fuzzy clustering method. The arcs (i.e., the paths of the public transportation) can be set up by using the shortest path model in the time sense or the 0 1 integer programming method.Applying the statistics method, we can calculate the parameters(such as the passenger flow's distribution, passenger flow's transition probability, mean waiting time for the bus etc. ) of the public transportation network. In this paper, we suggest to divide the network into two or three stages to implement the public transportation system in the form of ``frog jumping' fast transfer and ``permeation' fast dispersion.Combining the computer simulation and the evaluation of the achievement and effect of public transportation system, we modify the model so as to solve the public transportation problem better.展开更多
The integration of distributed generation brings in new challenges for the operation of distribution networks,including out-of-limit voltage and power flow control.Soft open points(SOP)are new power electronic devices...The integration of distributed generation brings in new challenges for the operation of distribution networks,including out-of-limit voltage and power flow control.Soft open points(SOP)are new power electronic devices that can flexibly control active and reactive power flows.With the exception of active power output,photovoltaic(PV)devices can provide reactive power compensation through an inverter.Thus,a synergetic optimization operation method for SOP and PV in a distribution network is proposed.A synergetic optimization model was developed.The voltage deviation,network loss,and ratio of photovoltaic abandonment were selected as the objective functions.The PV model was improved by considering the three reactive power output modes of the PV inverter.Both the load fluctuation and loss of the SOP were considered.Three multi-objective optimization algorithms were used,and a compromise optimal solution was calculated.Case studies were conducted using an IEEE 33-node system.The simulation results indicated that the SOP and PVs complemented each other in terms of active power transmission and reactive power compensation.Synergetic optimization improves power control capability and flexibility,providing better power quality and PV consumption rate.展开更多
The lack of current network dynamics studies that evaluate the effects of new application and protocol deployment or long-term studies that observe the effect of incremental changes on the Internet, and the change in ...The lack of current network dynamics studies that evaluate the effects of new application and protocol deployment or long-term studies that observe the effect of incremental changes on the Internet, and the change in the overall stability of the Internet under various conditions and threats has made network monitoring challenging. A good understanding of the nature and type of network traffic is the key to solving congestion problems. In this paper we describe the architecture and implementation of a scalable network traffic moni-toring and analysis system. The gigabit interface on the monitoring system was configured to capture network traffic and the Multi Router Traffic Grapher (MRTG) and Webalizer produces graphical and detailed traffic analysis. This system is in use at the Obafemi Awolowo University, IleIfe, Nigeria;we describe how this system can be replicated in another environment.展开更多
＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some pap...＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/展开更多
＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some pap...＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/展开更多
＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some pap...＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chirtese and English abstract, which can be downloaded after registration.展开更多
＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some pap...＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/展开更多
＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some pap...＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access;展开更多
＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some pap...＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/展开更多
＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some pap...＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration.展开更多
＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some pap...＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can he downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/展开更多
＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some pap...＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/展开更多
＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some pap...＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/展开更多
＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some pap...＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/展开更多
＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals,which covers all kinds of geological research fields of China.All papers of this site comprise English abstract,and some papers...＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals,which covers all kinds of geological research fields of China.All papers of this site comprise English abstract,and some papers have figures with English description.Papers present as the PDF format with two types：（1）papers can be downloaded for opening access;and（2）the others provide both Chinese and English abstract,which can be downloaded after registration.展开更多
Geoscience Periodical Network of China a"is s composed of 233 Chinese geological journals,which covers all kinds of geological research fi(elds of China.All papers of this site comprise English abstract,and some ...Geoscience Periodical Network of China a"is s composed of 233 Chinese geological journals,which covers all kinds of geological research fi(elds of China.All papers of this site comprise English abstract,and some papers have figures with English description.Papers present as the展开更多
基金supported by UniversitiKebangsaan Malaysia,under Dana Impak Perdana 2.0.(Ref:DIP–2022–020).
文摘Software Defined Networking(SDN)is programmable by separation of forwarding control through the centralization of the controller.The controller plays the role of the‘brain’that dictates the intelligent part of SDN technology.Various versions of SDN controllers exist as a response to the diverse demands and functions expected of them.There are several SDN controllers available in the open market besides a large number of commercial controllers;some are developed tomeet carrier-grade service levels and one of the recent trends in open-source SDN controllers is the Open Network Operating System(ONOS).This paper presents a comparative study between open source SDN controllers,which are known as Network Controller Platform(NOX),Python-based Network Controller(POX),component-based SDN framework(Ryu),Java-based OpenFlow controller(Floodlight),OpenDayLight(ODL)and ONOS.The discussion is further extended into ONOS architecture,as well as,the evolution of ONOS controllers.This article will review use cases based on ONOS controllers in several application deployments.Moreover,the opportunities and challenges of open source SDN controllers will be discussed,exploring carriergrade ONOS for future real-world deployments,ONOS unique features and identifying the suitable choice of SDN controller for service providers.In addition,we attempt to provide answers to several critical questions relating to the implications of the open-source nature of SDN controllers regarding vendor lock-in,interoperability,and standards compliance,Similarly,real-world use cases of organizations using open-source SDN are highlighted and how the open-source community contributes to the development of SDN controllers.Furthermore,challenges faced by open-source projects,and considerations when choosing an open-source SDN controller are underscored.Then the role of Artificial Intelligence(AI)and Machine Learning(ML)in the evolution of open-source SDN controllers in light of recent research is indicated.In addition,the challenges and limitations associated with deploying open-source SDN controllers in production networks,how can they be mitigated,and finally how opensource SDN controllers handle network security and ensure that network configurations and policies are robust and resilient are presented.Potential opportunities and challenges for future Open SDN deployment are outlined to conclude the article.
文摘In order to manage all kinds of network security devices and software systems efficiently, and make them collaborate with each other, the model for an open network security management platform is presented. The feasibility and key implementing technology of the model are expatiated. A prototype system is implemented to validate it.
基金funded in part by National Natural Science Foundation of China(grant NO.61471347)National S&T Mayor Project of the Ministry of S&T of China(grant NO.2016ZX03001020-003)+1 种基金key program for international S&T Cooperation Program of China(grant NO.2014DFA11640)Shanghai Natural Science Foundation(grant NO.16ZR1435100)
文摘Due to 5G's stringent and uncertainty traffic requirements,open ecosystem would be one inevitable way to develop 5G.On the other hand,GPP based mobile communication becomes appealing recently attributed to its striking advantage in flexibility and re-configurability.In this paper,both the advantages and challenges of GPP platform are detailed analyzed.Furthermore,both GPP based software and hardware architectures for open 5G are presented and the performances of real-time signal processing and power consumption are also evaluated.The evaluation results indicate that turbo and power consumption may be another challengeable problem should be further solved to meet the requirements of realistic deployments.
基金supported National Natural Science Foundation of China (Project Number: 61671086)Consulting Project of Chinese Academy of Engineering (Project Number: 2016-XY-09)
文摘There are an increasing of scenarios that require the independent bandwidth and delay demands. For instance, in a data center, the interactive message would not occupy much bandwidth, but it requires the rigorous demands for the delay. However, the existing QoS approaches are mainly bandwidth based, which are inappropriate for these scenarios. Hence, we propose the decoupled scheme in the OpenFlow networks to provide the centralized differential bandwidth and delay control. We leverage the mature HTB to manage the bandwidth. And we design the Queue Delay Management Scheme (QDMS) for queuing delay arrangement, as well as the Comprehensive Parameters based Dijkstra Route algorithm (CPDR) for the propagation delay control. The evaluation results verify the decoupling effectiveness. And the decoupled scheme can reduce the delay for high priority flows.
文摘In this paper, the open queueing network model is proposed for solving the problem of public transportation in cities. The vertices of the networks(i.e., the bus stops) are determined by means of the fuzzy clustering method. The arcs (i.e., the paths of the public transportation) can be set up by using the shortest path model in the time sense or the 0 1 integer programming method.Applying the statistics method, we can calculate the parameters(such as the passenger flow's distribution, passenger flow's transition probability, mean waiting time for the bus etc. ) of the public transportation network. In this paper, we suggest to divide the network into two or three stages to implement the public transportation system in the form of ``frog jumping' fast transfer and ``permeation' fast dispersion.Combining the computer simulation and the evaluation of the achievement and effect of public transportation system, we modify the model so as to solve the public transportation problem better.
基金supported by the Science and Technology Project of SGCC(kj2022-075).
文摘The integration of distributed generation brings in new challenges for the operation of distribution networks,including out-of-limit voltage and power flow control.Soft open points(SOP)are new power electronic devices that can flexibly control active and reactive power flows.With the exception of active power output,photovoltaic(PV)devices can provide reactive power compensation through an inverter.Thus,a synergetic optimization operation method for SOP and PV in a distribution network is proposed.A synergetic optimization model was developed.The voltage deviation,network loss,and ratio of photovoltaic abandonment were selected as the objective functions.The PV model was improved by considering the three reactive power output modes of the PV inverter.Both the load fluctuation and loss of the SOP were considered.Three multi-objective optimization algorithms were used,and a compromise optimal solution was calculated.Case studies were conducted using an IEEE 33-node system.The simulation results indicated that the SOP and PVs complemented each other in terms of active power transmission and reactive power compensation.Synergetic optimization improves power control capability and flexibility,providing better power quality and PV consumption rate.
文摘The lack of current network dynamics studies that evaluate the effects of new application and protocol deployment or long-term studies that observe the effect of incremental changes on the Internet, and the change in the overall stability of the Internet under various conditions and threats has made network monitoring challenging. A good understanding of the nature and type of network traffic is the key to solving congestion problems. In this paper we describe the architecture and implementation of a scalable network traffic moni-toring and analysis system. The gigabit interface on the monitoring system was configured to capture network traffic and the Multi Router Traffic Grapher (MRTG) and Webalizer produces graphical and detailed traffic analysis. This system is in use at the Obafemi Awolowo University, IleIfe, Nigeria;we describe how this system can be replicated in another environment.
文摘＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/
文摘＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/
文摘＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chirtese and English abstract, which can be downloaded after registration.
文摘＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/
文摘＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access;
文摘＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/
文摘＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration.
文摘＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can he downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/
文摘＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/
文摘＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/
文摘＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals, which covers all kinds of geological research fields of China. All papers of this site comprise English abstract, and some papers have figures with English description. Papers present as the PDF format with two types： （1） papers can be downloaded for opening access; and （2） the others provide both Chinese and English abstract, which can be downloaded after registration. Welcome to visit our website： http：//www.geojournals.cn/
文摘＂Geoscience Periodical Network of China＂ is composed of 233 Chinese geological journals,which covers all kinds of geological research fields of China.All papers of this site comprise English abstract,and some papers have figures with English description.Papers present as the PDF format with two types：（1）papers can be downloaded for opening access;and（2）the others provide both Chinese and English abstract,which can be downloaded after registration.
文摘Geoscience Periodical Network of China a"is s composed of 233 Chinese geological journals,which covers all kinds of geological research fi(elds of China.All papers of this site comprise English abstract,and some papers have figures with English description.Papers present as the
