ZTE High-end Routers Product Enters European Market

ZTE Corporation, the fastest growing global telecommunications equipment and network solutions provider, has been awarded a contract to

Diffserv AQM algorithm for edge and core routers

The existing active queue management （AQM） algorithm acts on subscribers and edge routers only, it does not support differentiate-serve （Diffserv） quality of service （QoS）, while the existing diffserv QoS has not considered the link capacities between edge routers and connected core routers. When a core router in a two layers’ network experiences congestion, the connected edge routers have no ability to adjust their access data rates. Thus, it is difficult to achieve the congestion control for the large scale network with many edge routers and core routers. To solve these problems, two difffserve AQM algorithms are proposed for the congestion control of multilayer network. One diffserv AQM algorithm implements fair link capacities of edge routers, and the other one implements unequal link capacities of edge routers, but it requires the core routers to have multi-queues buffers and Diffserv AQM to support. The proposed algorithms achieve the network congestion control by operating AQM parameters on the conditions of proposed three theorems for core and edge routers. The dynamic simulation results demonstrate the proposed control algorithms for core and edge routers to be valid.

DESIGN AND IMPLEMENTATION OF SINGLE-BUFFERED ROUTERS

A Single-Buffered （SB） router is a router where only one stage of shared buffering is sandwiched between two interconnects in comparison of a Combined Input and Output Queued （CIOQ） router where a central switch fabric is sandwiched between two stages of buffering. The notion of SB routers was firstly proposed by the High-Performance Networking Group （HPNG） of Stanford University, along with two promising designs of SB routers： one of which was Parallel Shared Memory （PSM） router and the other was Distributed Shared Memory （DSM） router. Admittedly, the work of HPNG deserved full credit, but all results presented by them appeared to relay on a Centralized Memory Management Algorithm （CMMA） which was essentially impractical because of the high processing and communication complexity. This paper attempts to make a scalable high-speed SB router completely practical by introducing a fully distributed architecture for managing the shared memory of SB routers. The resulting SB router is called as a Virtual Output and Input Queued （VOIQ） router. Furthermore, the scheme of VOIQ routers can not only eliminate the need for the CMMA scheduler, thus allowing a fully distributed implementation with low processing and commu- nication complexity, but also provide QoS guarantees and efficiently support variable-length packets in this paper. In particular, the results of performance testing and the hardware implementation of our VOIQ-based router （NDSC~ SR1880-TTM series） are illustrated at the end of this paper. The proposal of this paper is the first distributed scheme of how to design and implement SB routers publicized till now.

Area Analysis for On-chip Routers with Different Data-link Widths

Compared with the traditional and inter-chip networks, on-chip networks （NoCs） have enormous wire resources which can be traded for improving other performance requirements. This means that much wider data links can be used for NoCs. This paper focuses on the area costs for on-chip routers under four different data-link widths： 8 bits, 16 bits, 128 bits, and 256bits. Firstly, a virtual-channel based on-chip router is introduced. Secondly, the components of the router are implemented by Verilog HDL models and synthesized by Quartus II 4.0 in a FPGA device. Finally, the area costs are analyzed. It can be seen from the results that data-link width has great influence on area costs of buffers and crossbar while has no influence on area costs of arbiter.

Polarization and wavelength routers based on difractive neural network

In the feld of information processing,all-optical routers are signifcant for achieving high-speed,high-capacity signal processing and transmission.In this study,we developed three types of structurally simple and fexible routers using the deep difractive neural network(D2 NN),capable of routing incident light based on wavelength and polarization.First,we implemented a polarization router for routing two orthogonally polarized light beams.The second type is the wavelength router that can route light with wavelengths of 1550,1300,and 1100 nm,demonstrating outstanding performance with insertion loss as low as 0.013 dB and an extinction ratio of up to 18.96 dB,while also maintaining excellent polarization preservation.The fnal router is the polarization-wavelength composite router,capable of routing six types of input light formed by pairwise combinations of three wavelengths(1550,1300,and 1100 nm)and two orthogonal linearly polarized lights,thereby enhancing the information processing capability of the device.These devices feature compact structures,maintaining high contrast while exhibiting low loss and passive characteristics,making them suitable for integration into future optical components.This study introduces new avenues and methodologies to enhance performance and broaden the applications of future optical information processing systems.

Planning Model for Energy Routers Considering Peer-to-Peer Energy Transactions Among Multiple Distribution Networks

A high proportion of renewable energy affects the power quality of distribution networks,and surplus energy will be sold to the upstream grid at a low price.In this paper,considering peer-to-peer energy transactions,the energy router-based multiple distribution networks are analyzed to solve the above problems and realize collaborative consumption of renewable energy.Presently,the investing cost of an energy router is high,and research on the economic operation of energy routers in distribution networks is little.Therefore,this paper establishes a planning model for energy routers considering peer-to-peer energy transactions among distribution networks,and explores the benefits of peer-to-peer energy transactions through energy router based multiple distribution networks.A structure of an energy router suitable for peer-to-peer energy transactions is selected,and a power flow calculation model based on a multilayer structure is established.The energy router’s scheduling model is established,and unique functions of the energy router and revenue of each distribution network are considered.A power flow calculation model based on peer-to-peer interconnection of multiple distribution networks through energy routers is also established.Finally,simulation results verify the effectiveness of the proposed planning model.Results show that peer-topeer energy transaction among distribution networks through energy routers can effectively reduce the comprehensive cost of distribution networks,significantly improve the power quality of the distribution networks,and reduce the impact of power fluctuation on the upstream grid incurred by the distribution network.

Design and Analysis of Prioritized Medium Access Control Protocol for Backbone Routers in Wireless Mesh Networks

A Prioritized Medium Access Control （P-MAC） protocol is proposed for wireless routers of mesh networks with quality-of-service provisioning. The simple yet effective design of P-MAC offers strict service differentiation for prioritized packets. A Markov model is developed to yield important performance matrices including the packet blocking probability due to queue overflow and the packet reneging probability due to delay bound. It is further proved that the service time of P-MAC approximates exponential distribution, and can be effectively estimated. The analytic models with preemptive and non-preemptive schemes, validated via simulations, show that P-MAC can effectively support traffic differentiation and achieve very low packet dropping （both reneging and blocking） probabilities when the traffic load is below the channel capacity. When the network is overloaded, P-MAC can still maintain extremely stable and high channel throughput. Moreover, it is demonstrated that P-MAC performs superior in multihop networks, further proving the advantages of the proposed protocol.

A splitting-after-merging approach to multi-FIB compression and fast refactoring in virtual routers

Virtual routers are gaining increasing attention in the research field of future networks. As the core network device to achieve network virtualization, virtual routers have multiple virtual instances coexisting on a physical router platform, and each instance retains its own forwarding information base （FIB）. Thus, memory scalability suffers from the limited on-chip memory. In this paper, we present a splitting-after-merging approach to compress the FIBs, which not only improves the memory efficiency but also offers an ideal split position to achieve system refactoring. Moreover, we propose an improved strategy to save the time used for system rebuilding to achieve fast refactoring. Experiments with 14 real-world routing data sets show that our approach needs only a unibit trie holding 134 188 nodes, while the original number of nodes is 4 569 133. Moreover, our approach has a good performance in scalability, guaranteeing 90 000 000 prefixes and 65 600 FIBs.

Research on Next-Generation Scalable Routers Implemented with H-Torus Topology

The exponential growth of user traffic has been driving routers to run at higher capacity. In a traditional router, the centralized switching fabric is becoming the bottleneck for its limited number of ports and complicated scheduling algorithms. Direct networks, such as 3-D Torus topology, have been successfully applied to the design of scalable routers. They show good scalability and fault tolerance. Unfortunately, its scalability is limited in practice. In this paper, we introduce another type of direct network, called H-Torus. This network shows excellent topological properties. On its basis, the designs of line card and routing algorithms are introduced. Extensive simulations show that the routing algorithm is very important in such a system and results in low latency with high throughput.

Integrated Railway Smart Grid Architecture Based on Energy Routers

Railway power system is an inseparable part of the power system,therefore,the intelligent architecture of the railway power system should also be focused on.The unique power supply characteristics of the railway power system are analyzed and integrated railway smart grid architecture based on energy routers is proposed.Importantly,three corresponding resilient mode control methods are suggested for the proposed architecture.In the fourth section,a simulation model corresponding to the resilient control mode is built and the simulation results prove the feasibility of the proposed control mode.Equally,for the novel network-connected backbone router(NCBR),a 1000 kVA,27.5/10 kV NCBR engineering prototype is used to prove its effectiveness in practical applications.Finally,a differentiation analysis is given,followed by conclusions regarding the traditional power system and proposed system.

Dynamic modulated single-photon routing

The dynamic control of single-photon scattering in a pair of one-dimensional waveguides mediated by a time-modulated atom-cavity system is investigated.Two cases,where the waveguides are coupled symmetrically or asymmetrically to the atom-cavity system,are discussed in detail.The results show that such time-modulated atom-cavity configuration can behave as a dynamical tunable directional single-photon router.The photons with different frequencies can dynamically be routed from the incident waveguide into any ports of the other with a 100%probability via adjusting the modulated amplitude or phases of the time-modulated atom-cavity coupling strengths,associate with the help of the asymmetrical waveguide-cavity couplings.Furthermore,the influence of dissipation on the routing capability is investigated.It is shown that the present single-photon router is robust against the dissipative process of the system,especially the atomic dissipation.These results are expected to be applicable in quantum information processing and design quantum devices with dynamical modulation.

Performance enhancement of IEEE 802.11 distributed coordination function for MANET

The medium access control (MAC) issue was discussed in mobile Ad Hoc networks (MANETs). Based on the IEEE 802.11 MAC protocol, this paper proposed two schemes, the forward-packet-first (FPF) scheme based on the adaptive backoff contention window and multihop forward chain transmission by invitation (MFCTI) scheme. In the FPF scheme, the contention window was adjusted adaptively according to the traffic priority. Route information and the broadcast characteristic of radio were utilized in MFCTI scheme. The performance of these schemes was studied in multihop environments by simulations. The results showed that the proposed schemes could improve the network throughput, reduce the end-to-end average delay, and mitigate local congestion effectively. Another attractive feature was that the schemes could be implemented with minor modifications to the IEEE 802.11 MAC.

UNIX进程在PE与router间通信过程模拟中的应用

为提高Ａ－ＮＥＴ计算机的模拟速度，利用ＵＮＩＸ进程管理和进程通信的功能，编制了多进程模拟程序．若干个进程利用进程间传送信息的ｐｉｐｅ来实现同步．排斥控制由ｓｅｍａｐｈｏｒｅ来解决．使用ｐｉｐｅ、ＦＩＦＯ构成通信通道来实现进程间的数据交换．通信用命令的定义和数据传送过程的设定构成了通信协议．

簇式三维片上网络通信压力弱化策略

针对3D NoC中TSV衬垫面积大,TSV利用率低的特点,采用4个plane router共享一个TSV router的簇式结构,分时共享TSV;针对路由器故障,则提出一种在输入端口和输出端口间建立旁路的机制,当plane router的缓冲区和交叉开关故障时,数据包由旁路转发;对于TSV router故障,则通过增加数据分配器和多路选择器,进行加固;为弱化过热点,提出新的压力弱化模型,根据其自身通信量以及所处的位置,动态调整路由方向。仿真结果表明,与传统XYZ路由相比,无故障时平均网络延时减少21%～27%,有故障时减少20%～39%,吞吐率比minTSV提高约20%。

基于OSPF协议的大规模网络拓扑发现模型

针对传统大规模网络拓扑发现模型的准确性、完整性、实时性的局限性,借鉴OSPF协议周期性传播网络拓扑信息的机理,提出了基于OSPF协议的大规模网络拓扑发现模型LNTDM.该模型首先采用被动检测方式,通过获取OSPF协议中的链路状态更新报文,分析其中Router LSA、Network LSA获得区域内网络拓扑,然后通过边界路由获取的Summary Network LSA进行分析获得区域间网络拓扑,从而完成大规模网络拓扑结构的发现.实验结果表明,该模型能准确完整的获取大规模网络拓扑,可以很好的弥补现有大型网络拓扑发现技术的不足,实际应用前景广阔.

ApplianceBricks: A Scalable Network Appliance Architecture for Network Functions Virtualization

Network Functions Virtualization(NFV) is an attempt to help operators more effectively manage their networks by implementing traditional network functions embedded in specialized hardware platforms in term of virtualized software instances. But, existing novel network appliances designed for NFV infrastructure are always architected on a general-purpose x86 server, which makes the performance of network functions limited by the hosted single server. To address this challenge, we propose ApplianceB ricks, a novel NFV-enable network appliance architecture that is used to explore the way of consolidating multiple physical network functions into a clustered network appliance, which is able to improve the processing capability of NFV-enabled network appliances.

MARS:A General Multilayer Area Router

Based on a ripped-up and rerouted methodology,a multilayer area detailed router is presented by using simulated evolution technique.A modified maze algorithm is also performed for the single net.

基于P-R模型的网络计费系统的实现

本文提出了一种基于P-R模型的网络计费方法,它将Proxy的计费和Router的计费结合起来的计费方式。解决了单一计费方式的缺陷,同时减轻了由校网络中心统一计费的负担。并且可与学校的财务系统互连,实现自动代扣代缴。

Router OS网络工程组建及管理

随着我国信息经济快速发展,电脑再也不是奢饰品,已经走进了人们的生活。为了方便人们对电脑的使用,大量的电脑系统也因此诞生,其中,Router OS是一款在策略路由、无线应用、宽带控制等方面都具备着极高的功能性与性价比的软件,深受人们的喜欢与欢迎。本文就以Router OS为主,分析了Router OS性能优势,着重探讨了用户如何对Router OS网络工程的组建及管理工作。

VRRP路由协议介绍及配置

作为信息化应用的载体——计算机网络的可靠性受到越来越多的重视.VRRP(虚拟路由器冗余协议)是一种选择协议,它的优势在于不需要在终端进行动态路由和路由发现协议的配置,即可获得一个高可靠性的缺省路由通道.通过以S9300系列交换机为载体,分析和研究VRRP虚拟路由器冗余性协议的原理和配置,实现园区网络的路由冗余.