域名系统(domain name system,DNS)是互联网的核心基础设施,其解析可靠性直接影响网络服务的可用性与用户体验。然而,随着DNS的功能扩展与体系结构复杂度的增加,DNS解析失败日益频发。现有针对DNS解析失败的研究较为碎片化,缺乏系统性...域名系统(domain name system,DNS)是互联网的核心基础设施,其解析可靠性直接影响网络服务的可用性与用户体验。然而,随着DNS的功能扩展与体系结构复杂度的增加,DNS解析失败日益频发。现有针对DNS解析失败的研究较为碎片化,缺乏系统性的归纳与方法论支撑。鉴于此,从协议实施缺陷、配置错误、域名滥用、网络与管理问题4个维度提出分类归因框架,系统地刻画了DNS解析失败的成因与特征。基于该框架,结合互联网工程任务组发布的请求评议标准与典型案例,提出了协议一致性测试、自动化配置校验、域名信誉评分、高可用部署架构等缓解思路,为DNS故障诊断和防护提供系统化的分析视角与实践参考。展开更多
The wide diffusion of mobile devices that natively support ad hoc communication technologies has led to several protocols for enabling and optimizing Mobile Ad Hoc Networks (MANETs). Nevertheless, the actual utilizati...The wide diffusion of mobile devices that natively support ad hoc communication technologies has led to several protocols for enabling and optimizing Mobile Ad Hoc Networks (MANETs). Nevertheless, the actual utilization of MANETs in real life seems limited due to the lack of protocols for the automatic creation and evolution of ad hoc networks. Recently, a novel P2P protocol named Wi-Fi Direct has been proposed and standardized by the Wi-Fi Alliance to facilitate nearby devices’ interconnection. Wi-Fi Direct provides high-performance direct communication among devices, includes different energy management mechanisms, and is now available in most Android mobile devices. However, the current implementation of Wi-Fi Direct on Android has several limitations, making the Wi-Fi Direct network only be a one-hop ad-hoc network. This paper aims to develop a new framework for multi-hop ad hoc networking using Wi-Fi Direct in Android smart devices. The framework includes a connection establishment protocol and a group management protocol. Simulations validate the proposed framework on the OMNeT++ simulator. We analyzed the framework by varying transmission range, number of hops, and buffer size. The results indicate that the framework provides an eventual 100% packet delivery for different transmission ranges and hop count values. The buffer size has enough space for all packets. However, as buffer size decreases, the packet delivery decreases proportionally.展开更多
文摘域名系统(domain name system,DNS)是互联网的核心基础设施,其解析可靠性直接影响网络服务的可用性与用户体验。然而,随着DNS的功能扩展与体系结构复杂度的增加,DNS解析失败日益频发。现有针对DNS解析失败的研究较为碎片化,缺乏系统性的归纳与方法论支撑。鉴于此,从协议实施缺陷、配置错误、域名滥用、网络与管理问题4个维度提出分类归因框架,系统地刻画了DNS解析失败的成因与特征。基于该框架,结合互联网工程任务组发布的请求评议标准与典型案例,提出了协议一致性测试、自动化配置校验、域名信誉评分、高可用部署架构等缓解思路,为DNS故障诊断和防护提供系统化的分析视角与实践参考。
文摘The wide diffusion of mobile devices that natively support ad hoc communication technologies has led to several protocols for enabling and optimizing Mobile Ad Hoc Networks (MANETs). Nevertheless, the actual utilization of MANETs in real life seems limited due to the lack of protocols for the automatic creation and evolution of ad hoc networks. Recently, a novel P2P protocol named Wi-Fi Direct has been proposed and standardized by the Wi-Fi Alliance to facilitate nearby devices’ interconnection. Wi-Fi Direct provides high-performance direct communication among devices, includes different energy management mechanisms, and is now available in most Android mobile devices. However, the current implementation of Wi-Fi Direct on Android has several limitations, making the Wi-Fi Direct network only be a one-hop ad-hoc network. This paper aims to develop a new framework for multi-hop ad hoc networking using Wi-Fi Direct in Android smart devices. The framework includes a connection establishment protocol and a group management protocol. Simulations validate the proposed framework on the OMNeT++ simulator. We analyzed the framework by varying transmission range, number of hops, and buffer size. The results indicate that the framework provides an eventual 100% packet delivery for different transmission ranges and hop count values. The buffer size has enough space for all packets. However, as buffer size decreases, the packet delivery decreases proportionally.
