软件定义网络(software defined networking,SDN)分离的数据平面和控制平面,给网络管理带来了开放性和灵活性.但同时控制器与交换机之间的接口(控制器南向接口)需要更频繁的交互各种消息以实现对网络的控制.一方面,数据平面触发Table-M...软件定义网络(software defined networking,SDN)分离的数据平面和控制平面,给网络管理带来了开放性和灵活性.但同时控制器与交换机之间的接口(控制器南向接口)需要更频繁的交互各种消息以实现对网络的控制.一方面,数据平面触发Table-Miss的数据包需要通过Packet-In消息往返于交换机与控制器之间,时延增大的同时也给控制器南向接口带来繁重的通信开销,数据平面和控制平面之间的交互容易成为网络性能的瓶颈.另一方面,控制器在下发新的流表项时,由于缺乏新表项对应的数据流特征信息,易出现已有的大流表项被下发的小流表项替换的情况,造成冗余的Flow-Mod消息(流表更新消息)和Packet-In消息,进一步加重了南向接口的通信开销,降低了网络的整体性能.提出一种基于流量特征的OpenFlow南向接口开销优化技术uFlow,在控制器上通过对Packet-In消息中数据流量特征的识别以及对小流的直接转发,达到消除南向接口冗余开销的目的.对uFlow的原型系统进行了实现,并通过真实网络中的流量对uFlow优化效果进行了验证.实验结果显示:与传统的OpenFlow网络处理方式相比,uFlow消除了冗余的交换机流表项更新,显著地降低了OpenFlow南向接口的交互开销:在不同的网络负载和流表容量的情况下,uFlow平均能减少70%以上的Flow-Mod消息.展开更多
This article seeks to answer why Taiwan has targeted Southeast Asia in its external economic strategy,and how the China factor has influenced the development of Taiwan-ASEAN economic relations.Worried about the politi...This article seeks to answer why Taiwan has targeted Southeast Asia in its external economic strategy,and how the China factor has influenced the development of Taiwan-ASEAN economic relations.Worried about the political and economic risks inherent in Taiwan’s growing economic dependence on China,as well as Taiwan’s marginalization in regional economic integration,Taiwan Residents presidents since Lee have all emphasized the need to enhance trade and investment ties with Association of Southeast Asian Nations(ASEAN)countries.While the complementary natures of Taiwan’s and Southeast Asia’s economies place Taiwan in a favorable position to“Go South”,sovereign disputes in cross-Strait relations prevent the island from negotiating bilateral or multilateral trade agreements with ASEAN countries.The article argues that hedging is the most rational and viable option for Taiwan to manage political and economic analysis of Southeast Asian regional economic integration and under China’s rise.The article examines the four major components of this strategy,namely,economic pragmatism,direct engagement,hard balancing,and soft balancing.The article goes on to assess the significance of each component and details how Taiwan has pursued its hedging strategy towards Southeast Asian regional economic integration.展开更多
软件定义网络(Software Defined Network,SDN)是实现网络智能化的基础与主要技术途径。当前,商用的SDN网络一般应用于数据中心与软件定义广域网(Software-Defined WAN,SD-WAN)场景,其协议设计着眼于宽带、有线、固定的使用环境,普遍存...软件定义网络(Software Defined Network,SDN)是实现网络智能化的基础与主要技术途径。当前,商用的SDN网络一般应用于数据中心与软件定义广域网(Software-Defined WAN,SD-WAN)场景,其协议设计着眼于宽带、有线、固定的使用环境,普遍存在网络开销大,无法适应动态组网,很难应用于窄带、弱连接的战术边缘场景。基于此,文中在主流商用SDN协议的基础上,从控制平面自动构建、轻量化协议设计与业务流量调度等方面设计了一套面向战术边缘应用的、轻量化的SDN网络控制平面接口协议,仿真验证了所提方案的优越性。文中的研究可为智能化战术信息网络的设计提供一定的参考。展开更多
文摘软件定义网络(software defined networking,SDN)分离的数据平面和控制平面,给网络管理带来了开放性和灵活性.但同时控制器与交换机之间的接口(控制器南向接口)需要更频繁的交互各种消息以实现对网络的控制.一方面,数据平面触发Table-Miss的数据包需要通过Packet-In消息往返于交换机与控制器之间,时延增大的同时也给控制器南向接口带来繁重的通信开销,数据平面和控制平面之间的交互容易成为网络性能的瓶颈.另一方面,控制器在下发新的流表项时,由于缺乏新表项对应的数据流特征信息,易出现已有的大流表项被下发的小流表项替换的情况,造成冗余的Flow-Mod消息(流表更新消息)和Packet-In消息,进一步加重了南向接口的通信开销,降低了网络的整体性能.提出一种基于流量特征的OpenFlow南向接口开销优化技术uFlow,在控制器上通过对Packet-In消息中数据流量特征的识别以及对小流的直接转发,达到消除南向接口冗余开销的目的.对uFlow的原型系统进行了实现,并通过真实网络中的流量对uFlow优化效果进行了验证.实验结果显示:与传统的OpenFlow网络处理方式相比,uFlow消除了冗余的交换机流表项更新,显著地降低了OpenFlow南向接口的交互开销:在不同的网络负载和流表容量的情况下,uFlow平均能减少70%以上的Flow-Mod消息.
文摘This article seeks to answer why Taiwan has targeted Southeast Asia in its external economic strategy,and how the China factor has influenced the development of Taiwan-ASEAN economic relations.Worried about the political and economic risks inherent in Taiwan’s growing economic dependence on China,as well as Taiwan’s marginalization in regional economic integration,Taiwan Residents presidents since Lee have all emphasized the need to enhance trade and investment ties with Association of Southeast Asian Nations(ASEAN)countries.While the complementary natures of Taiwan’s and Southeast Asia’s economies place Taiwan in a favorable position to“Go South”,sovereign disputes in cross-Strait relations prevent the island from negotiating bilateral or multilateral trade agreements with ASEAN countries.The article argues that hedging is the most rational and viable option for Taiwan to manage political and economic analysis of Southeast Asian regional economic integration and under China’s rise.The article examines the four major components of this strategy,namely,economic pragmatism,direct engagement,hard balancing,and soft balancing.The article goes on to assess the significance of each component and details how Taiwan has pursued its hedging strategy towards Southeast Asian regional economic integration.
文摘软件定义网络(Software Defined Network,SDN)是实现网络智能化的基础与主要技术途径。当前,商用的SDN网络一般应用于数据中心与软件定义广域网(Software-Defined WAN,SD-WAN)场景,其协议设计着眼于宽带、有线、固定的使用环境,普遍存在网络开销大,无法适应动态组网,很难应用于窄带、弱连接的战术边缘场景。基于此,文中在主流商用SDN协议的基础上,从控制平面自动构建、轻量化协议设计与业务流量调度等方面设计了一套面向战术边缘应用的、轻量化的SDN网络控制平面接口协议,仿真验证了所提方案的优越性。文中的研究可为智能化战术信息网络的设计提供一定的参考。
