MTU和MSS问题研究

如果网络不丢包而网络时快时慢,或部分应用无法使用,很大程度上可以定位为MTU&MSS问题。文章从MTU和MSS原理分析了问题产生的原因,提出了解决问题的方法。     

市电子政务外网改造故障分析及解决办法

本文从TCP/IP协议角度对市电子政务外网改造过程中,对由MTU引起故障进行讨论,分析了故障产生的原因,并给出解决方法。     

在MCU中通过特殊硬件进行电机控制

电流电机控制的主芯片可以大致分为三类:纯DSP、纯MCU和MCU+DSP.基于三种芯片的电机解决方案各有特点.本文使用了一种有别于上述主芯片的单芯片MTU进行电机控制设计,从控制电机同步、测量电机两相电流等应用介绍了用MTU进行设计的方案特点.     

Stationary Fuel Cells at Work – An Interim Report

Different fuel cell systems, in various numbers, have been installed and run at customers' sites using natural gas. Operational results from these field tests are presented, which demonstrate that several fuel cell systems can be used successfully to generate heat and electricity. Improved reliability and cutting costs are the most urgent challenges for commercialisation.     

A review on the clad failure studies

In this paper, an attempt has been made to systematically organize the research investigations conducted on clad tube failure, so far. Before presenting the review on the clad failure studies, an introduction to different clad materials has been added, in which the effect of alloying elements on the material properties have been presented. The literature on clad failure has been broadly categorized under the headings LOCA and RIA. The failure mechanisms like creep, corrosion and pellet-clad interaction have been discussed in details. Each subsection of the review has been provided with summary table, in which the studies are arranged in the chronological order. A small section on acceptance criteria for ECCS has also been included. The last section of the review has been dedicated to the core-degradation phenomena.     

基于防火墙的路径MTU发现问题研究

通过分析路径MTU发现机制,本文深入剖析了复杂网络环境中由于防火墙、路由器等网关设备存在而引起的端到端访问异常的问题,结合FW3000防火墙设计了FAPM模型,并通过实际测试和理论分析证明了这个模型解决复杂网络环境中PMTU发现问题的有效性。     

Rate limitable and efficient discovery of path maximum transmission units

Path maximum transmission unit discovery (PMTUD) is the protocol by which a host can find the largest packet it can send through an internet protocol (IP) network to a given destination. It relies on intermediary nodes sending “packet too big” (PTB) messages in IPv6 or “datagram too big” messages in IPv4 (both henceforth referred to as PTB for the purposes of this paper). These are often completely blocked by firewalls, presumably due to a fear of PTB floods wasting the bandwidth of network links. This breaks PMTUD, forcing the use of fragmentation in IPv4 and/or suboptimal packet sizes. In IPv6, fragmentation by intermediary nodes is no longer an option. Utilizing a dynamic programming‐based solution to the generalization of a mathematical puzzle, the two‐egg problem, this work presents a family of strategies for a host to discover path MTU while obeying hard limits on the maximum number of incoming PTB messages that may be generated. This allows a firewall to mitigate PTB floods via rate limits. Moreover, these strategies are compliant with the relevant standards on PMTUD and thus can be deployed by merely changing the PMTUD algorithm implementation in TCP/IP stacks on end hosts without changing intermediary nodes' protocol behavior.     

基于CANopen协议的柴油机控制系统

在详细阐述CANopen协议的基础上,介绍CANopen协议在MTU柴油机控制系统上的应用,以及基于CANopen协议下通讯软件的设计方法。     

应用IPv6路径MTU探测时的防火墙设计

“路径MTU探测”是IPv6的一个非常重要的特征。IPv6分组不能被中介路由器分割。源主机必须知道通往目标主机通路上的最小MTU。为此源主机必须使用MTU探测，也就是用ICMPv6的“包太大”报文来发现MTU。如果防火墙挡住ICMPv6包的话，将导致MTU探测无法正确执行。这需要防火墙可以识别出与连接有关的ICMPv6信息。该文提出了一种方法可以解决这个问题，并对相关的安全问题进行了探讨。     

隧道模型下MTU问题的研究

提出了一种IPv4-IPv6-Tunnel的特定隧道模型,并针对该模型的实例就IPv4和IPv6两种接入情形,着重讨论了其中隧道MTU的发现和错误处理机制,给出相关比较。描述了模型的实现和MTU测试结果,总结了其可能的应用。