针对命名数据网络(named data networking,NDN)中,路由节点缓存利用的不合理、无法区分内容请求频率的高低,导致路由节点缓存命中率过低的问题,提出了一种基于新鲜因子的缓存替换策略(FRESH)。FRESH策略通过在包结构中新增内容类型、跳...针对命名数据网络(named data networking,NDN)中,路由节点缓存利用的不合理、无法区分内容请求频率的高低,导致路由节点缓存命中率过低的问题,提出了一种基于新鲜因子的缓存替换策略(FRESH)。FRESH策略通过在包结构中新增内容类型、跳数、动态时间3个Tag字段,引入信息熵衡量数据类型的优先级,利用新增Tag字段构建新的替换参量——“新鲜因子”,设计新的缓存替换策略。实验结果表明,在缓存容量比为0.03、Zipf分布参数为0.8的环境下,FRESH策略与DCVRP、CPCA相比较,缓存命中率分别增长了3.5%和6%,明显的提高了缓存命中率,优化了网络中的缓存效率。展开更多
The rise of time-sensitive applications with broad geographical scope drives the development of time-sensitive networking(TSN)from intra-domain to inter-domain to ensure overall end-to-end connectivity requirements in...The rise of time-sensitive applications with broad geographical scope drives the development of time-sensitive networking(TSN)from intra-domain to inter-domain to ensure overall end-to-end connectivity requirements in heterogeneous deployments.When multiple TSN networks interconnect over non-TSN networks,all devices in the network need to be syn-chronized by sharing a uniform time reference.How-ever,most non-TSN networks are best-effort.Path delay asymmetry and random noise accumulation can introduce unpredictable time errors during end-to-end time synchronization.These factors can degrade syn-chronization performance.Therefore,cross-domain time synchronization becomes a challenging issue for multiple TSN networks interconnected by non-TSN networks.This paper presents a cross-domain time synchronization scheme that follows the software-defined TSN(SD-TSN)paradigm.It utilizes a com-bined control plane constructed by a coordinate con-troller and a domain controller for centralized control and management of cross-domain time synchroniza-tion.The general operation flow of the cross-domain time synchronization process is designed.The mecha-nism of cross-domain time synchronization is revealed by introducing a synchronization model and an error compensation method.A TSN cross-domain proto-type testbed is constructed for verification.Results show that the scheme can achieve end-to-end high-precision time synchronization with accuracy and sta-bility.展开更多
文摘针对命名数据网络(named data networking,NDN)中,路由节点缓存利用的不合理、无法区分内容请求频率的高低,导致路由节点缓存命中率过低的问题,提出了一种基于新鲜因子的缓存替换策略(FRESH)。FRESH策略通过在包结构中新增内容类型、跳数、动态时间3个Tag字段,引入信息熵衡量数据类型的优先级,利用新增Tag字段构建新的替换参量——“新鲜因子”,设计新的缓存替换策略。实验结果表明,在缓存容量比为0.03、Zipf分布参数为0.8的环境下,FRESH策略与DCVRP、CPCA相比较,缓存命中率分别增长了3.5%和6%,明显的提高了缓存命中率,优化了网络中的缓存效率。
基金supported in part by National Key R&D Program of China(Grant No.2022YFC3803700)in part by the National Natural Science Foundation of China(Grant No.92067102)in part by the project of Beijing Laboratory of Advanced Information Networks.
文摘The rise of time-sensitive applications with broad geographical scope drives the development of time-sensitive networking(TSN)from intra-domain to inter-domain to ensure overall end-to-end connectivity requirements in heterogeneous deployments.When multiple TSN networks interconnect over non-TSN networks,all devices in the network need to be syn-chronized by sharing a uniform time reference.How-ever,most non-TSN networks are best-effort.Path delay asymmetry and random noise accumulation can introduce unpredictable time errors during end-to-end time synchronization.These factors can degrade syn-chronization performance.Therefore,cross-domain time synchronization becomes a challenging issue for multiple TSN networks interconnected by non-TSN networks.This paper presents a cross-domain time synchronization scheme that follows the software-defined TSN(SD-TSN)paradigm.It utilizes a com-bined control plane constructed by a coordinate con-troller and a domain controller for centralized control and management of cross-domain time synchroniza-tion.The general operation flow of the cross-domain time synchronization process is designed.The mecha-nism of cross-domain time synchronization is revealed by introducing a synchronization model and an error compensation method.A TSN cross-domain proto-type testbed is constructed for verification.Results show that the scheme can achieve end-to-end high-precision time synchronization with accuracy and sta-bility.
