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Industrial-grade 4G router TCP/IP network architecture 1. Layering of TCP/IP network system   TCP/IP (TransmissionControlProtocol/InternetProtocol), transmission control protocol/Internet protocol. It was developed by the defense advanced research projects agency in the 1970s, and was later integrated into UNIX and popularized. It emerged in the 1980s as the Internet's...

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The structure of 4G DTU The main function of DTU is to transmit data from remote devices back to the background center via wired/wireless. Different data transmission modes of DTU include all-network-connected DTU, GPRS DTU, WIFI DTU, CAN DTU and 4G DTU. Today, we will have a look at the structure and work flow of DTU.   To complete...

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What are the wireless connection technologies of the... Internet of things (iot) applications have been deeply rooted in our lives. The E-Lins H685 industrial-grade router is a small industrial-grade wireless router with single or double LAN ports. TDD/ fdd-lte, 4G, 3G, GPRS network optional. Besides, what are the wireless connectivity technologies for the Internet of things?   1....

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The use of industrial wireless routers Industrial-grade wireless router adopts high performance 32-bit industrial-grade ARM9 communication processor, which is widely used in finance, electric power, postal, water conservancy, environmental protection, meteorology and other industries.   Industrial router is mainly used in intelligent transportation,...

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Cascade and stack of industrial-grade 4G routers The most basic star Ethernet architecture, the actual star enterprise network may be much more complex than this. This renaturation is not only reflected in how high-end network equipment, how complex configuration, more importantly, the performance of network switching level is more complex. Industrial routers and firewalls...

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工业级路由器LSP校验和(Checksum)

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工业路由器生成一个LSP后,为了保证LSP中信息的完整性,它将对LSP进行校验和计算,然后封装进LSP的LSP校验和字段(checksum)。校验和的计算包括从LSP中的剩余时间字段之后的字段一直到数据包的末尾,由于剩余时间是一个不断变化的字段,所以校验和计算将不包括这部分内容。校验和主要用于检查被破坏的LSP或者还没有从网络中清除的过期LSP。当一台工业4g路由器收到一个LSP,在将该LSP放入到本地链路数据库和将其再泛洪给其他邻接工业3G路由器之前,会重新计算LSP的校验和,如果校验和与LSP中携带的校验和不一致,则说明此全网通工业级路由器LSP传输过程中已经被破坏。

当工业路由器收到了一个被破坏的LSP后,会采取一个清除的操作。它将该LSP的剩余时间设置为0然后再泛洪到网络中。当网络中的其他工业LTE路由器收到这个剩余时间被置为0的LSP后,会将其本地链路状态数据库中相应的LSP清除。当产生这个被破坏的LSP的源双卡路由器收到这个剩余时间被置为0的LSP并发现这个LSP是自己生成的后,会重新生成一个正确的LSP然后泛洪到网络中。

IS-IS的这种LSP清除操作虽然可以有效的清除网络中被破坏的LSP,给运行工业级4G路由器IS-IS路由协议的网络提供了一种自动修复的能力,但是它也带来了一种负面的影响。如果网络中的介质存在问题,就有可能产生LSP被连续破坏的现象。这些被破坏的LSP会被路由器不断的清除,同时源工业无线路由器也会不断的重新生成新的LSP,这种现象被称为LSP破坏风暴。LSP破坏风暴将消耗大量的网络资源。我们可以对工业级无线路由器进行配置,使其在收到被破坏的LSP后忽略它,即丢弃被破坏的LSP,从而启动清除操作。在后续工业级全网通路由器IS-IS配置章节中将介绍具体的配置方法。

标签:4g路由器    4g DTU

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