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Dual SIM Router vs. Dual Radio Router Projects are looking to save their enterprises time and money ask us this very often: “When would I need to use dual SIMs, and in what situations should I consider dual radio dual sim router?” In order to make this clear, let’s take a quick look at the dual SIM and dual SIM dual radio module functionality. Dual...

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工业路由器NBMA网络转化为点到点的链路 当我们使用点到点子接口将NBMA网络转化为点到点的链路时,整个NBMA网络将产生过多的PVC部分互联或全互联的网状结构,但这将产生一定的负面影响,会使网络中产生大量的LSP泛洪流量。我们都知道,运行IS-IS的工业路由器当接收到一个LSP报文后,会将此LSP从除接收接口以外的所有启用了IS-IS协议的接口泛洪出去,以使网络中的其他工业路由器都可以接收到此LSP。但是这种泛洪机制对于存在大量部分互联或全互联的网络将产生过多冗余的LSP扩散。 所谓全互联或全网状网络拓扑,是指所有工业路由器都与其他工业级无线路由器向连接(通常是点到点子接口)。在这样的一个网络中,当一台路由器从某接口收到邻居泛洪过来的LSP后,由于它并不知道这个LSP是否已经被其他邻居工业4g路由器收到,所以会再从其他接口泛洪出去,即使其他工业级4g路由器的链路状态数据库中已经存在这个LSP。如果网络中有n个全网路由器的话,那么网络中的每台工业级LTE路由器都会扩散n-2条冗余的LSP,这样总共被泛洪的多余的LSP将为(n-1)x(n-2),条而这些LSP的扩散是多余。如果每台工业全网通路由器都刷新一条LSP的话,那么这个数量还将会成倍数的增长,导致了大量带宽资源的浪费。 为了解这种在全互联或高度互联的网络中出现的LSP泛洪的冗余现象,IS-IS提供了一种解决方案——IS-IS全通组,也称作Mesh组。IS-IS全通组在RFC2973中进行了定义。所谓全通组,就是假设所有工业3G路由器之间都是完全互联的,每个工业级全网通路由器都会直接收到其他全网通工业级路由器泛洪的原始的LSP的拷贝。 可以将全网工业路由器的接口加入到某个全通组中,一个全网通工业路由器上可以存在多个全通组,全通组内接口之间的LSP泛洪是受限制的,全通组之间的LSP泛洪是正常的操作,未加入全通组的工业级3G路由器接口与全通组之间也是正常的LSP泛洪操作。全网通路由器 ...

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工业路由器使用CSNP来保证链路状态数据库的完整性 在广播网络中,工业路由器使用CSNP来保证链路状态数据库的完整性,并且只有DIS才会发送工业全网通路由器CSNP报文,DIS发送CSNP报文的间隔为10s。CSNP报文中描述了DIS的链路状态数据库中所有工业级3G路由器LSP的摘要信息。当其他工业级路由器收到DIS发送的CSNP后,会使用CSNP中的LSP摘要信息与与本地的链路状态数据库中的LSP进行比较,进行比较的目的是确定本地链路状态数据库中的信息是否已经同步和完整。如果工业级4g路由器发现本地数据库中缺少某个LSP条目,那么它将使用PSNP向DIS请求这个缺少的LSP条目。这个PSNP报文中包含就是请求的LSP条目的摘要信息。当DIS收到其他全网路由器发送的PSNP报文后,将会发送一个完整的LSP报文,这个LSP就是其他工业无线路由器所缺少的LSP条目。在广播网络中,DIS使用周期性的CSNP报文向网络中发送同步链路状态数据库的信号,而其他工业4g路由器使用PSNP报文来请求缺少的LSP条目。 在IS-IS的点到点类型的网络中,链路状态数据库同步的操作与广播网络中略有不同,而且工业级全网通路由器发送CSNP与PSNP报文的方式和其作用也有一些差别。 在点到点网络中不存在DIS,工业3G路由器不会周期性的发送CSNP报文,CSNP报文只在链路链路被激活时发送一次,而且链路两端的工业级4g路由器都会发送CSNP报文以描述本地链路状态数据库中所有LSP的摘要信息。当工业路由器发送对端发送的CSNP中含有本地缺少的LSP信息时,也会使用PSNP报文向对端请求LSP。当对端收到PSNP报文后,将向请求方发送包含完整LSP信息的LSP报文,这点上与广播网络中的操作是相同的。但是在点到点链路上,收到LSP报文的工业4g路由器还会向对方再次发送一个PSNP报文以对之前收到的LSP进行确认。可以说,在点到点网络中的LSP交换是可靠的。这点与广播网络不同,在广播网络中工业级无线路由器不使用PSNP报文对收到的LSP进行确认,而是通过DIS周期性地发送CSNP报文以弥补广播网络中不可靠的LSP交换。 在点到点链路上,工业路由器使用PSNP对收到的LSP报文进行确认,所以在点到点链路上是可靠的泛洪机制。 IS-IS路由协议支持两种网络类型:广播链路和点到点链路。默认情况下,全网通工业级路由器IS-IS将广播网络和NBMA网络看作是广播类型。对于封装了PPP或HDCL等协议的链路看作是点到点类型。对于NBMA网络中的主接口和点到多点子接口,IS-IS将其看作是广播类型;对于NBMA网络中的点到点子接口,将其看作是点到点类型。IS-IS不像OSPF那样,提供了对NBMA网络(例如Frame-Relay、ATM)的专门支持。对于NBMA网络,全网通工业路由器IS-IS认为其网络拓扑是PVC全互联(mesh)的,就是把它看作广播网络。但如果实际网络拓扑中并不是PVC全互联的结构时,例如部分互联的结构和Hub-Spoke结构,推荐使用点到点类型网络,即使用点到点子接口,以免造成NBMA网络中的链路状态数据库同步出现问题。无线路由器

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工业级路由器LSP校验和(Checksum) 当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...

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伊林思:中间系统类型工业4G路由器(ISType) 在LSP报头中最后一个字节的中间系统类型(ISType)位占2bit,工业4G路由器的类型。该字段表示了此LSP是来自L1工业路由器还是L2工业级路由器。这也表示了收到此LSP的工业路由器将把这个LSP放到L1链路状态数据库还是L2链路状态数据库。该2bit中01表示L1;11表示L2;00与10未使用。 DIS和伪节点【4g路由器】 LSPID中包括一部分称为伪节点标识符(PseudonodeID),用来标识此LSP是否是由网络中的指定中间系统(DIS,DesignatedIntermediateSystem)为网络产生的伪节点LSP。 在广播类型的网络(LAN)中,IS-IS需要为每个网段选择一个指定中间系统DIS,这里的指定中间系统DIS的作用与OSPF中的指定工业级路由器DR的非常相似。在OSPF网络中,DR用来负责将链路状态信息泛洪到每个非DR工业路由器,并且帮助其进行链路状态数据库的同步。在IS-IS中也是如此,为了使链路状态信息更加准确和实时的同步给网络中的所有全网路由器,并且要减小带宽的利用率和路由器的处理开销,IS-IS也要在广播网络中选举出一个工业级无线路由器(DIS)来达到这个目的。 在IS-IS中选举DIS的过程也是非常简单的。每个运行IS-IS协议的全网通路由器的接口都拥有一个优先级(Priority),默认的优先级为64,同样也可以通过命令手工修改默认的优先级。工业4g路由器之间发送的HelloPDU中将携带接口的优先级信息。每个工业LTE路由器收到网络中其他工业级LTE路由器发送的HelloPDU后,通过比较优先级来进行DIS的选举。优先级数值越大的工业全网路由器将被选举为此网段的DIS。这里与OSPF不同的是,在OSPF中,如果接口的优先级为0,那么这台工业级全网通路由器将被认为没有资格成为此网段的DR。在IS-IS中,如果接口的优先级为0,这仅仅表示最低的优先级,但是此工业级4G路由器还拥有成为DIS的资格。当两台工业全网通路由器的接口优先级相同时,那么拥有更大的SNPA(在LAN中通常为MAC地址)的接口的工业级全网通路由器将成为DIS。在OSPF中如果优先级相同将比较RouterID。 在OSPF中,选举完DR后,还将选举出一个备份DR,BDR(BackupDR),以用来在原先DR出现故障时接替新的DR角色,并重新选举出BDR。但在IS-IS中,将不进行备份DIS的选举。如果DIS出现故障了,其他全网通工业路由器将会重新选举出一个DIS。其次,在OSPF中,DR和BDR的选举是非抢占模式的,也就是说当有更优优先级的路由器加入到现有网络中后,也不会抢占原先DR和BDR的角色。从某种意义上来讲,在OSPF网络中,第一台启动的双卡路由器将成为网络的DR,第二台启动的双路路由器将将成为BDR。与OSPF相比,DIS的选举是抢占的,即当有更优DIS资格双路路由器加入网络后,它会成为网络中新的DIS。这样,每次DIS的变更必须泛洪一组新的LSP。 默认情况下,运行IS-IS的双卡路由器将以每10s的间隔发送HelloPDU。但是对于一个DIS来说,由于它在网络中起到重要的作用,所以它发送HelloPDU的间隔的频率将是其他路由器的3倍,也就是说DIS以每3.3s的间隔发送HelloPDU。这样其他全网通工业路由器可以迅速检测出DIS出现故障并开始新的选举过程,增加了网络的收敛速度。无线路由器

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E-Lins FAQ — POE

Category : 产品文章, 伊林思产品FAQ, 其他, 技术相关

Q: Does your router support POE option? How does it work?

A: Yes, E-lins H685 series, H700 series and H720 series routers support POE option.

It works as following chart.

POE

 

Antenna Gain

Category : 其他

For a better understanding about antenna gain, you can go through this article.

Antenna gain is often quoted with respect to a hypothetical antenna that radiates equally in all directions, an isotropic radiator. This gain, when measured in decibels, is called dBi. Conservation of energy dictates that high gain antennas must have narrow beams. For example, if a high gain antenna makes a 1 watt transmitter look like a 100 watt transmitter, then the beam can cover at most 1/100 of the sky (otherwise the total amount of energy radiated in all directions would sum to more than the transmitter power, which is not possible). In turn this implies that high-gain antennas must be physically large, since according to the diffraction limit, the narrower the beam desired, the larger the antenna must be (measured in wavelengths).

Antenna gain can also be measured in dBd, which is gain in Decibels compared to the maximum intensity direction of a half wave dipole. In the case of Yagi type aerials this more or less equates to the gain one would expect from the aerial under test minus all its directors and reflector. It is important not to confuse dBi and dBd; the two differ by 2.15 dB, with the dBi figure being higher, since a dipole has 2.15 db of gain with respect to an isotropic antenna.

Gain is also dependent on the number of elements and the tuning of those elements. Antennas can be tuned to be resonant over a wider spread of frequencies but, all other things being equal, this will mean the gain of the aerial is lower than one tuned for a single frequency or a group of frequencies. For example, in the case of wideband TV antennas the fall off in gain is particularly large at the bottom of the TV transmitting band. In the UK this bottom third of the TV band is known as group A, see gain graph comparing grouped aerials to a wideband aerial of the same size/model.

Other factors may also affect gain such as aperture (the area the antenna collects signal from, almost entirely related to the size of the antenna but for small antennas can be increased by adding a ferrite rod), and efficiency (again, affected by size, but also resistivity of the materials used and impedance matching). These factors are easy to improve without adjusting other features of the antennas or coincidentally improved by the same factors that increase directivity, and so are typically not emphasized.

E-Lins router has stardard 3dbi cellular antenna. This is enough for normal use. If you want to put it in rural place or place with bad reception, it’s better to get a high gain antenna.

Orange helps Sensile Tech monitor Oil & Gas with M2M

Category : 其他, 技术相关

About Sensile Technologies

Sensile Technologies is a forerunner in the Internet of Things (IoT) market and a leading provider of solutions for remote monitoring of tank levels for the oil and propane industry. Founded in 1999 and based in Morges, Switzerland, Sensile Technologies has extensive experience in high-quality product development and production as well as reliable service and support. They are an innovative company with four world premieres under their belt. All of their products are Swiss made and certified for hazardous environments.

 

About Orange Business Services

Orange Business Services, the Orange branch dedicated to B2B services, is not only a telecom operator, but also an IT solutions integrator and applications developer in France and around the world. Its 20,000 employees support companies in all areas of their digital transformation: mobile and collaborative workspaces; IT/cloud infrastructure; fixed and mobile connectivity; private and hybrid networks; applications for Internet of Things, 360° customer experience and Big Data analytics; and cybersecurity thanks to dedicated experts and infrastructure to protect information systems. More than 3,000 multinational organizations and 2 million SOHOs, enterprises and local authorities in France rely on Orange Business Services as their trusted partner.

 

Orange is one of the world’s leading telecommunications operators with annual sales of 40 billion euros in 2015 and has 155,000 employees worldwide at 31 March 2016. Orange is listed on the NYSE Euronext Paris (symbol ORA) and on the New York Stock Exchange (symbol ORAN).

Orange and any other Orange product or service names included in this material are trademarks of Orange or Orange Brand Services Limited.

 

 

Orange Business Services has won a three-year contract with Sensile Technologies for M2M connectivity, including 25,000 SIM cards, to support its two remote monitoring products worldwide: NETRIS®2 and GASLink®

Headquartered in Morges, Switzerland, Sensile Technologies is a pioneer in the internet of things (IoT) market. Specifically, it is a leading provider of solutions for the remote monitoring of tanks and meters in the oil and gas industry. Sensile Technologies monitors more than 60,000 tanks in industrial and business facilities across 60 countries, via a global network of highly-qualified technicians and local partners.

Up to now, Sensile Technologies used 2G compatible devices to power its telemetry solutions. The contract with Orange Business Services extends this to cover 3G/4G devices, which future-proofs the solutions against 2G network shutdown and ensures seamless global coverage.

Sensile Technologies’ telemetry solutions, GASLink® and NETRIS®2, play a key role in the monitoring process. They are installed directly in the oil or propane tank and regularly send tank level measurements via the GSM network to the cloud, where the data is automatically processed.

The up-to-date tank level data allows oil and propane merchants – and their haulers – to arrange deliveries automatically via planning tools. They get data directly in their enterprise resource planning (ERP) system from Sensile Technologies’ Oil Link cloud solution to trigger deliveries automatically. In addition, their customers can get access on smartphones to monitor consumption.

Thanks to the optimization of deliveries based on live data, merchants and haulers can lower their logistics costs by at least 25 percent, without the risk of customers running dry. In addition to mitigating the risk of running out of fuel, customers are also able to access a detailed visualization and analysis of their logistics, enabling them to adapt their processes to reduce their costs further.

“Leading oil and propane companies rely on our autonomous, robust, and easy to install systems. We have more than 60,000 in place on tanks in over 60 countries. Orange Business Services has proven itself as a reliable partner with the global footprint we need for our business. Their competitive flat-fee pricing was convincing as well,” said Jean-Marc Uehlinger, Operational Director, Sensile Technologies.

“With its telemetry solutions Sensile Technologies is helping drive the latest revolution in industry. In Industry 4.0 every part of the enterprise and each phase of the manufacturing cycle will be connected. The internet of things (IoT) and M2M play a key part in this revolution, and we manage 10 million connected objects for our customers worldwide, including over 7 million active SIM cards,” Anne-Sophie Lotgering, senior vice president Europe, Russia & CIS, Orange Business Services.

GASLink® and NETRIS®2 are the result of 15 years’ experience from Sensile Technologies in the development and production of autonomous telemetry equipment. In addition to using the 2G (SMS) network to transmit data, NETRIS®2 can also use 3G or 4G, as well as create a short-distance radio frequency connection, which functions in every location.

PPPoE–Point-to-point protocol over Ethernet

Category : 其他, 技术相关

The Point-to-Point Protocol over Ethernet (PPPoE) is a network protocol for encapsulating PPP frames inside Ethernet frames. It appeared in 1999, in the context of the boom of DSL as the solution for tunneling packet sover the DSL connection to the ISP’s IP network, and from there to the rest of the Internet. A 2005 networking book noted that “Most DSL providers use PPPoE, which provides authentication, encryption, and compression.” Typical use of PPPoE involves leveraging the PPP facilities for authenticating the user with a username and password, predominately via the PAP protocol and less often via CHAP.

On the customer-premises equipment, PPPoE may be implemented either in a unified residential gateway device that handles both DSL modem and IP routing functions or in the case of a simple DSL modem (without routing support), PPPoE may be handled behind it on a separate Ethernet-only router or even directly on a user’s computer. (Support for PPPoE is present in most operating systems, ranging from Windows XP, Linux to Mac OS X.) More recently, some GPON-based (instead of DSL-based) residential gateways also use PPPoE, although the status of PPPoE in the GPON standards is marginal.

PPPoE was developed by UUNET, Redback Networks (now Ericsson) and RouterWare (now Wind River Systems) and is available as an informational RFC 2516.

In the world of DSL, PPPoE was commonly understood to be running on top of ATM (or DSL) as the underlying transport, although no such limitation exists in the PPPoE protocol itself. Other usage scenarios are sometimes distinguished by tacking as a suffix another underlying transport. For example, PPPoEoE, when the transport is Ethernet itself, as in the case of Metro Ethernet networks. (In this notation, the original use of PPPoE would be labeled PPPoEoA, although it should not be confused with PPPoA, which is a different encapsulation protocol.)

PPPoE has been described in some books as a “layer 2.5″ protocol, in some rudimentary sense similar to MPLS because it can be used to distinguish different IP flows sharing an Ethernet infrastructure, although the lack of PPPoE switches making routing decision based on PPPoE headers limits applicability in that respect.

Nokia #India announces #5G #IoT for #SmartCities

Category : 其他, 技术相关

The Finnish company showcased more than 60 different use-cases of these technologies at its annual Innovation Day in Bengaluru, including those that are already live and ready for use as well as ones that aren’t live yet.

Nokia’s research and development office in Bengaluru, which has around 5,000 employees, creates solutions for both its Indian and international markets. Its new IoT range, though, will focus more on Indian clients, especially governments.

“5G and IoT are going to be the future trends that we see in the marketplace. While from an India standpoint it’s still an early stage for 5G to happen, IoT is taking a bit of a step forward in terms of adoption here,” Randeep Raina, chief technology officer for Nokia India said in an interview on Wednesday.

“There are certain initiatives led by the government right now in the form of digital India and smart city programs. IoT could be one of the enablers to make cities a bit safer and smarter. It’s with that intent that we’d put a theme out here on this innovation day,” he said.

The three main solutions, or use-cases, showcased by the company on Wednesday were video analytics of real-time city surveillance, a public safety service that can be deployed at railroad crossings and a smart parking service.

Based on real-time city surveillance via cameras deployed at various public locations Nokia’s IoT solution will be able to provide clients – mostly governments and policing authorities – with data analysis. The analysis includes everything from identifying anomalies, such as incorrect pedestrian crossings, to tracking traffic patterns.

Its public safety solution uses sensors, beacons and cameras and is aimed at keeping pedestrians from straying across the path of oncoming trains at railroad crossings. This service will both warn people crossing railroads on foot of an oncoming train as well as alert the authorities and issue notice of a fine in case people cross even after receiving a warning. The warning messages will appear on any device using any service provider and are not app-based, i.e. the user will not need to install an app to see the messages.

Nokia’s smart parking solution will target organized parking lots that can use it to fully automate the process – from identifying a car on entry and guiding the driver to free parking spots through an app, to recording the number of hours a car is parked at the lot and bill payment online via the app.

Roughly two months ago, auto components supplier Bosch Ltd also launched solutions targeted at creating smart cities, including a smart parking service that will help commuters find space in crowded areas. The German company has other similar solutions that are, again, aimed at assisting traffic policing and citizen safety and security systems.

M2M Magazine  http://www.machinetomachinemagazine.com/2016/12/15/nokia-india-announces-5g-iot-for-smartcities/

Research: China IoT Market is expected to Worth 121.45 Billion USD by 2022

Category : 其他, 技术相关

According to the new market research report China IoT Market by Hardware (Processor, Memory, Logic, Sensor, & Connectivity), Software (Real-Time Streaming, Network Security, Data Management, Remote Monitoring, & Bandwidth Management), Platform, Service, and Application – Global Forecast to 2022,published by MarketsandMarkets, the market is expected to reach USD 121.45 Billion by 2022, at a CAGR of 41.1% between 2016 and 2022.

The major factors driving this market are the growing demand for smartphone and other connecting devices, the increasing internet penetration, rising trends of industrial automation, and mainstream adoption of cloud computing.

A Brief Introduction of US largest Operator Verizon

Category : 其他, 技术相关

Verizon Communications, Inc. (simply known as Verizon), is a broadband telecommunications company and the largest U.S. wireless communications service provider as of September 2014, and a corporate component of the Dow Jones Industrial Average. The company is based at 1095 Avenue of the Americas in Midtown Manhattan, New York City, but is incorporated in Delaware.

 

What eventually became Verizon was founded as Bell Atlantic, which was one of the seven Baby Bells that were formed after AT&T Corporation was forced to relinquish its control of the Bell System by order of the Justice Department of the United States. Bell Atlantic came into existence in 1984 with a footprint from New Jersey to Virginia, with each area having a separate operating company (consisting of New Jersey Bell, Bell of Pennsylvania, Diamond State Telephone, and C&P Telephone).

 

As part of the rebranding that the Baby Bells took in the mid-1990s, all of the operating companies assumed the Bell Atlantic name. In 1997, Bell Atlantic expanded into New York and the New England states by merging with fellow Baby Bell NYNEX. In addition, Bell Atlantic moved their headquarters from Philadelphia into the old NYNEX headquarters and rebranded the entire company as Bell Atlantic.

 

In 2000, Bell Atlantic merged with GTE, which operated telecommunications companies across most of the rest of the country that was not already in Bell Atlantic’s footprint. Bell Atlantic, the surviving company, changed its name to “Verizon”, a portmanteau of veritas (Latin for “truth”) and horizon.

 

As of 2016, Verizon is one of three companies that had their roots in the former Baby Bells. The other two, like Verizon, exist as a result of mergers among fellow former Baby Bell members. One, SBC Communications, bought out its former parent AT&T Corporation and assumed the AT&T name. The other, CenturyLink, was formed initially in 2011 by the acquisition of Qwest (formerly named US West).

LTE CAT4/CAT6释义

Category : 其他, 技术相关

LTE CAT4/CAT6释义

  LTE CAT全名LTE UE-Category,拆开来解释, LTE指的是4G LTE网络、UE是指用户设备、Category翻译为等级。通顺解释就是用户设备能够支持的4G LTE网络传输速率的等级,也可以说成是4G网络速度的一个技术标准。所以LTE CAT4/CAT6就是指用户设备LTE网络接入能力等级为4或6。

  既然等级不同,那么其能力也肯定是不一样的,下面我们来看看LTE CAT4/CAT6影响了什么性能,分别是什么水平。简单来说,LTE CAT影响的就是4G LTE上行、下行网络速度的上限,通俗来讲就用户设备所能达到的上传、下载速度最大值。

r_4912859[1]

  在LTE CAT中不仅有4、6两个等级,上表是我们罗列的目前已知的LTE CAT等级以及对应的最大传输速度。其中LTE CAT4/CAT6也是目前4G手机的网络传输技术水平,而速度更快的CAT7和CAT8则仍处于实验室阶段,并未商用开发。

  

What is OpenWrt

Category : 其他, 技术相关

OpenWrt is an embedded operating system based on the Linux kernel, primarily used on embedded devices to route network traffic. The main components are the Linux kernel, util-linux, uClibc or musl, and BusyBox. All components have been optimized for size, to be small enough for fitting into the limited storage and memory available in home routers.
OpenWrt is configured using a command-line interface (ash shell), or a web interface (LuCI). There are about 3500 optional software packages available for installation via the opkg package management system.
OpenWrt can run on various types of devices, including CPE routers, residential gateways, smartphones, pocket computers (e.g. Ben NanoNote), and laptops. It is also possible to run OpenWrt on personal computers, which are most commonly based on the x86 architecture.
History
The project came into being because Linksys built the firmware for their WRT54G series of wireless routers from publicly available code licensed under the GPL. Under the terms of that license, Linksys was required to make the source code of its modified version available under the same license, which in turn enabled independent developers to create additional derivative versions. Support was originally limited to the WRT54G series, but has since been expanded to include many other chipsets, manufacturers and device types, including Plug Computers and Openmoko mobile phones.
Using this code as a base and later as a reference, developers created a Linux distribution that offers many features not previously found in consumer-level routers. Some features formerly required proprietary software. Before the introduction of OpenWrt 8.09, using Linux 2.6.25 and the b43 kernel module, WLAN for many Broadcom-based routers was only available through the proprietary wl.o module that was also provided for Linux kernel version 2.4.x only.
The code names of OpenWrt branches are named after alcoholic beverages, usually including their recipes in the MOTD as well, cf. White Russian, Kamikaze, Backfire, Attitude Adjustment, Barrier Breaker.
The bleeding edge development trunk was confusingly also called Kamikaze until February 2011 but with r25514 it was renamed as “Attitude Adjustment” and is now being constantly renamed to the next stable name.
Features
OpenWrt follows the bazaar-philosophy and is known for an abundance of options. Features include:
• A writable root file system, enabling users to add, remove or modify any file. This is accomplished by using overlayfs to overlay a read-only compressed SquashFS file system with a writable JFFS2 file system in a copy-on-write fashion. JFFS2 supports flash wear leveling.
• The package manager opkg, similar to dpkg, enables users to install and remove software. The package repository contains about 3500 packages. This contrasts with Linux-based firmwares based on read-only file systems without the possibility to modify the installed software without rebuilding and flashing a complete firmware image.
• A set of scripts called UCI (unified configuration interface) intended to unify and simplify the configuration of the entire system
• Extensible configuration of the entire hardware drivers, e.g. built-in network switches and their VLAN-capabilities, WNICs, DSL modems, FX, available hardware buttons, etc.
• Exhaustive possibilities to configure network-related features, like:
• IPv4 support.
• IPv6 native stack:
• Prefix Handling,
• Native IPv6 configuration (SLAAC, stateless DHCPv6, stateful DHCPv6, DHCPv6-PD),
• IPv6 transitioning technologies (6rd, 6to4, 6in4, ds-lite, lw4o6, map-e),
• Downstream IPv6 configuration (Router Advertisement, DHCPv6 (stateless and stateful) and DHCPv6-PD).
• Routing through iproute2, Quagga, BIRD, Babel etc.
• Mesh networking through B.A.T.M.A.N., OLSR and IEEE 802.11s-capabilities of the WNIC drivers
• Wireless functionality, e.g. make the device act as a wireless repeater, a wireless access point, a wireless bridge, a captive portal, or a combination of these with e.g. ChilliSpot, WiFiDog Captive Portal, etc.
• Wireless security: Packet injection, e.g. Airpwn, lorcon, e.a.
• Stateful firewall, NAT and port forwarding through netfilter; additionally PeerGuardian is available
• Dynamically-configured port forwarding protocols UPnP and NAT-PMP through upnpd, etc.
• Port knocking via knockd and knock
• TR-069 (CWMP) client
• IPS via Snort (software)
• Active queue management (AQM) through the network scheduler of the Linux kernel, with many available queuing disciplines. CoDel has been backported to Kernel 3.3. This encapsulates Traffic shaping to ensure fair distribution of bandwidth among multiple users and Quality of Service (QoS) for simultaneous use of applications such as VoIP, online gaming, and streaming media without experiencing the negative impacts of link saturation.
• Load balancing for use with multiple ISPs using source-specific routing
• IP tunneling (GRE, OpenVPN, pseudowire, etc.)
• Extensible realtime network monitoring and statistics through e.g. RRDtool, Collectd, Nagios, Munin lite, Zabbix, etc.
• Domain Name System (DNS) and DHCP through Dnsmasq, MaraDNS, etc.
• Dynamic DNS services to maintain a fixed domain name with an ISP that does not provide a static IP address
• Wireless distribution system (WDS) including WPA-PSK, WPA2-PSK, WPA-PSK/WPA2-PSK Mixed-Mode encryption modes
• OpenWrt supports any hardware that has Linux support; devices that can be connected (e.g. over USB) to an embedded device include
• Printers
• Mobile broadband modems
• Webcams
• Sound cards
• Notable software packages to use the hardware support are:
• File sharing via SAMBA, (Windows-compatible), NFS and FTP, printer sharing over the print server CUPS (spooling) or p910nd (non-spooling)
• PulseAudio, Music Player Daemon, Audio/Video streaming via DLNA/UPnP AV standards, iTunes (DAAP) server
• Asterisk (PBX)
• MQ Telemetry Transport through Mosquitto
• An extensive Ajax-enabled web interface, thanks to the LuCI project
• Regular bug fixes and updates, even for devices no longer supported by their manufacturers

 

Link to E-Lins OpenWrt Products:

http://www.e-lins.com/EN/download/H685_Datasheet_Eng.pdf

http://www.e-lins.com/EN/download/H820_Datasheet_Eng.pdf

http://www.e-lins.com/EN/download/H850_Datasheet_Eng.pdf

http://www.e-lins.com/EN/download/H860_Datasheet_Eng.pdf

无线路由器待机能耗超空调是否属实

Category : 其他

深圳市伊林思科技有限公司网络编辑部与大家分享: 无线路由器待机能耗超空调是否属实,另外我们公司一直努力为广大客户提供一下最优质的产品与服务:
工业路由器
lte路由器
4g路由器
3g路由器

 

无线路由器待机能耗超空调是否属实
家里来了朋友,朋友看见我家里安装了无线路由器,在闲聊的时候,朋友告诉我无线路由器待机能耗太大了,已经超出空调的能耗,笔者一听还真是吓一跳,在网上一查,却是有这样的谣传,但是也有辟谣的说法。那么到底无线路由器待机能耗是不是真的超过空调呢?我们来看一下的报道就清楚了。
南方都市报最新报道,近日,网络上流传着无线路由器“待机能耗”大于空调的说法,网友纷纷互相提醒,路由器不用时要关好。南都记者向一业内工程师求证得知,路由器一接电源即满载工作,并无“待机”一说。
家用无线路由器年耗电仅仅30-60度
“据测量,液晶电视的每小时待机能耗为0 .7瓦,卧室(空调)为0 .8瓦。最令人意想不到的是无线路由器,每小时待机能耗竟然有4瓦,远远大于电视机和空调。路由器如果一年不关,消耗35 .04度电。”该说法近期在微博上被转发多次。
某路由器生产商技术支持部工程师江先生介绍,一般有遥控器、智能开关的家电才有“待机”状态,无线路由器并无“待机”一说,接上电源基本就会满载工作。一般家庭用无线路由器,若整年不关,用电30-60度。
不用时关闭能让网速变快
江先生表示,对电子产品来说,长期开机对使用寿命有一定影响;而时不时关闭、重启路由器,可清空其内存、利于其降温散热,使上网速度变快。
其介绍,路由器像电脑一样,也包含C PU、内存、Flash(类似电脑硬盘)等部分,若长时间运行,内存中会存有大量数据,若厂商的软件编写不太完善,这些数据在一定时间内得不到释放,会造成新连接无法建立,就使用户感觉开网页、下载东西变慢。
另外,夏天室内气温高,若路由器本身主动散热性能不佳,也可能造成上网慢的感觉。此时若切断电源,冷却一段时间后重新开机,会有一定改善。
其他有遥控器的大家电,的确有待机状态浪费电的问题。多位节电专家提醒,电视、空调等家电产品,不用时应将插座拔掉,或使用特制的节电插座,消除待机状态的能耗。
通过以上的媒体报道内容,我们也了解到了家用无线路由器年耗电仅仅30-60度,就算是60度电,一年的电费也才30多元钱,所以大家没有必要轻易相信网络谣传。