您是否注意到与我们仅使用常规4G 网络相比，连接到(4G network)Wi-Fi时您的互联网速度会提高？嗯，你要感谢Wi-Fi路由器，它让我们的浏览体验无缝。根据您居住的国家/地区，速度差异可能是两倍甚至更多。我们生活在一个互联网速度飞速增长的时代，以至于现在我们以千兆(Gigabits)比特来衡量我们的互联网速度，而不是几年前的千比特。随着无线市场中不断涌现的令人兴奋的新技术的出现，我们很自然地期望我们的无线设备会有所改进。
什么是无线路由器？
简而言之，Wi-Fi 路由器只不过是一个带有短天线的小盒子，它有助于在整个房子或办公室内传输互联网。
路由器是一种硬件设备，充当调制解调器和计算机之间的桥梁。顾名思义，它在您使用的设备和互联网之间路由流量。选择正确类型的路由器在确定最快的互联网体验、防范网络威胁、防火墙等方面起着重要作用。
如果您不具备路由器工作原理的技术知识，那完全没问题。让我们从一个简单的例子来了解路由器的工作原理。
您可能拥有各种各样的设备，例如智能手机、笔记本电脑、平板电脑、打印机、智能电视(TVs)等等，这些设备可以连接到互联网。这些设备共同构成了一个称为 局域网(Local Area Network) (LAN) 的网络。 ((LAN). )LAN上存在越来越多的设备会导致使用的各种设备消耗不同的带宽，这可能会导致某些设备的 Internet 延迟或中断。
这就是路由器通过以最有效的方式引导传入和传出流量来无缝地跨这些设备传输信息的地方。
路由器的主要功能之一是充当计算机之间的 集线器或交换机 (Hub or Switch )，允许它们之间的数据同化和传输无缝发生。
为了处理所有这些大量的传入和传出数据，路由器必须是智能的，因此路由器本身就是一台计算机，因为它具有 CPU 和内存， (CPU & Memory, )有助于处理传入和传出数据。
典型的路由器执行各种复杂的功能，例如
- 提供来自防火墙的最高安全级别
- (Data)使用相同互联网连接的计算机或网络设备之间的数据传输
- 允许同时在多个设备上使用互联网
路由器有什么好处？(What are the benefits of a Router?)
1. 提供更快的 wifi 信号(1. Delivers faster wifi signals)
现代 Wi-Fi 路由器使用通常具有 2.4 GHz至 5 GHz范围的第 3 层设备，这有助于提供比以前的标准更快的 Wi-Fi 信号和扩展范围。
2. 可靠性(2. Reliability)
路由器隔离受影响的网络，并通过其他运行良好的网络传递数据，这使其成为可靠的来源。
3. 便携性(3. Portability)
无线路由器通过发送 Wi-Fi 信号消除了与设备进行有线连接的需要，从而确保了连接设备网络的最高便携性。
有两种不同类型的路由器：
a) 有线路由器：(a) Wired router:)它通过允许路由器分发信息的专用端口使用电缆直接连接到计算机
b) 无线路由器：(b) Wireless Router:)它是一种现代路由器，通过天线在连接到其局域网的多个设备上无线分发信息。
要了解路由器的工作原理，我们需要首先查看组件。路由器的基本组件包括：
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CPU： 是路由器的主控制器，执行路由器操作系统的命令。它还有助于系统初始化、网络接口控制等。
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ROM： 只读存储器包含引导程序和开机(Power)诊断程序（POST）
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RAM： 随机存取存储器存储路由表和运行配置文件。在打开和关闭路由器电源时， RAM的内容会被删除。
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NVRAM： 非易失性RAM保存启动配置文件。与RAM不同，它即使在路由器打开和关闭后也会存储内容
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闪存：(Flash Memory:) 它存储操作系统的图像并作为可重新编程的ROM 工作。(ROM.)
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网络接口：(Network Interfaces:) 接口是物理连接端口，可以将不同类型的电缆连接到路由器，如以太网、光纤分布式数据接口(Fiber distributed Data interface)( FDDI )、综合服务数字网络 ( ISDN ) 等。
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总线：(Buses:) 总线充当CPU和接口之间的通信桥梁，有助于数据包的传输。
路由器的功能是什么？(What are the functions of a Router?)
路由(Routing )
路由器的主要功能之一是通过路由表中指定的路由转发数据包。
它使用某些称为静态路由的内部预配置指令在传入和传出接口连接之间转发数据。
路由器还可以使用动态路由，根据系统内的条件通过不同的路由转发数据包。
与动态路由相比，静态路由为系统提供了更高的安全性，因为除非用户手动更改路由表，否则路由表不会更改。
推荐：(Recommended:) 修复无线路由器不断断开或掉线(Fix Wireless Router Keeps Disconnecting Or Dropping)
路径确定(Path determination)
路由器会考虑多种选择以到达同一目的地。这称为路径确定。路径确定考虑的两个主要因素是：
为了确定最佳路径，路由器在路由表中搜索与目标数据包的 IP 地址完全匹配的网络地址。
路由表(Routing tables )
路由表有一个网络智能层，它指导路由器将数据包转发到目的地。它包含帮助路由器以最佳方式到达目标 IP 地址的网络关联。路由表包含以下信息：
- 网络 ID(Network Id) – 目标 IP 地址
- Metric – 必须沿其发送数据包的路径。
- 跃点 -(Hop –)是数据包必须通过其发送才能到达最终目的地的网关。
安全(Security )
路由器使用防火墙为网络提供额外的安全层，防止任何类型的网络犯罪或黑客攻击。防火墙是一种专门的软件，可以分析来自数据包的传入数据并保护网络免受网络攻击。
路由器还提供虚拟专用网络 (VPN)(Virtual Private Network (VPN))，为网络提供额外的安全层，从而生成安全连接。
转发表(Forwarding table )
转发是数据包跨层传输的实际过程。路由表有助于选择可能的最佳路由，而转发表则将路由付诸行动。
路由如何工作？(How does Routing work?)
- 路由器读取传入数据包的目的IP地址
- 根据这个传入的数据包，它使用路由表选择适当的路径。
- 然后使用转发表将数据包通过跃点转发到最终目标 IP 地址。
简而言之，路由是使用所需信息以最佳方式将数据包从目的地A传输到目的地B的过程。
转变(Switch)
交换机在相互连接的设备之间共享信息方面起着非常重要的作用。交换机通常用于所有设备连接在一起形成局域网(Local Area Network)( LAN ) 的大型网络。与路由器不同，交换机仅将数据包发送到用户配置的特定设备。
我们可以通过一个小例子来了解更多：(We can understand more with a small example : )
假设您想在WhatsApp上向您的朋友发送照片。一旦您发布您朋友的照片，来源和目标 IP 地址就确定了，并且照片被分成小块，称为必须发送到最终目的地的数据包。
路由器使用路由和转发算法帮助找出将这些数据包传输到目标 IP 地址的最佳方式，并管理整个网络的流量。如果一条路由拥塞，路由器会找到所有可能的替代路由，将数据包传送到目标 IP 地址。
无线路由器(Wi-Fi Routers)
今天，我们周围的 Wi-Fi 接入点比历史上任何时候都多，所有这些接入点都在竭力为越来越多的数据需求量大的设备提供服务。
Wi-Fi 信号非常多，有强有弱，如果我们用特殊的方式看到它，周围的空域就会受到很多污染。
现在，当我们进入机场、咖啡店、活动等高密度和高需求区域时，使用无线设备的多个用户的集中度会增加。尝试上网的人越多，接入点为满足大量激增的需求而承受的压力就越大。这会减少每个用户可用的带宽并显着降低速度，从而导致延迟问题。
Wi-Fi 802.11 系列(802.11 family of Wi-Fi)可以追溯到 1997 年，此后对 Wi-Fi 的每次性能改进更新都在三个方面进行，这也被用作跟踪改进的指标，它们是(Wi-Fi)
调制(The modulation) 是塑造模拟波以传输数据的过程，就像任何上下起伏直到到达我们耳朵（接收器）的音频一样。这个特定的波由一个频率定义，其中幅度和相位被修改以向目标指示唯一的信息位。因此，频率越高，连接性越好，但就像声音一样，如果其他声音的干扰是我们的无线电信号，我们只能做很多事情来增加音量，质量会受到影响。
空间流 (Spatial Streams )就像从同一个河流源头流出的多条水流。河源可能很强大，但一条溪流无法承载这么多的水，所以将它分成多条溪流，以达到在共同保护区汇合的最终目标。
Wi-Fi 使用多个天线来实现这些，其中多个数据流同时与目标设备交互，这被称为MIMO（多输入 - 多输出）(MIMO (Multiple Input – Multiple Output))
当这种交互发生在多个目标之间时，它被称为多用户(Multi-User)( MU-MIMO )，但这里有一个问题，“目标需要彼此相距足够远”。
在任何给定时间，网络在单个通道上运行， 通道绑定(Channel Bonding) 只不过是结合特定频率的较小细分以增加目标设备之间的强度。无线频谱(Spectrum)非常受限于特定的频率和频道。不幸的是，大多数设备运行在相同的频率上，所以即使我们增加通道绑定，也会有其他外部干扰会降低信号质量。
另请阅读：(Also Read:) 如何找到我的路由器的 IP 地址？(How to Find My Router’s IP Address?)
Wi-Fi 6 与其前身相比有何不同？(What is different about Wi-Fi 6 over its predecessor?)
简而言之，在速度、可靠性、稳定性、连接数量和功率效率方面有所改进。
如果我们更深入地研究它，我们会开始注意到使Wi-Fi 6如此通用的原因是 增加了第四个指标 Airtime Efficiency(addition of 4th metric Airtime Efficiency)。所有这些，我们都没有考虑到无线频率的有限资源。因此，设备将填充比所需更多的频道或频率，并且连接的时间比所需的长得多，简单来说，这是一个非常低效的混乱。
Wi-Fi 6 (802.11 ax) 协议通过OFDMA（正交频分多址）(OFDMA (Orthogonal frequency-division multiple access))解决了这个问题， 其中数据传输经过优化和组合，仅使用请求的所需资源量。这由接入点(Access Point)分配和控制，以传递目标请求的数据有效载荷，并利用下行链路(Downlink)和上行链路(Uplink) MU-MIMO（多用户、多输入、多输出）(MU-MIMO (multi-user, multiple inputs, multiple outputs))来提高设备之间数据传输的效率。利用OFDMA，Wi-Fi设备可以在本地网络上以更高的速度同时并行发送和接收数据包。
数据的并行传输以极其有效的方式提高了跨网络的数据传输能力，而不会导致现有下行链路速度下降。
我的旧 WI-FI 设备会怎样？(What will happen to my old WI-FI devices?)
这是国际(International)Wi-Fi联盟(Alliance)于2019 年 9 月(September 2019)制定的Wi-Fi新标准。Wi-Fi 6 向后兼容，但有一些外观变化。
我们连接的每个网络都以不同的速度、延迟和带宽运行，这些网络由 802.11 后面的某个字母表示，例如 802.11b、802.11a、802.11g、802.11n 和 802.11ac(802.11, such as 802.11b, 802.11a, 802.11g, 802.11n and 802.11ac)，即使是我们中最好的人也感到困惑。
Wi-Fi 6结束了所有这些混乱，Wi-Fi联盟用这个改变了命名约定。在此之前的每个Wi-Fi版本都将在Wi-Fi 1-5 之间进行编号，以便于表达。
结论(Conclusion)
充分了解路由器的工作原理有助于我们导航和解决路由器和Wi-Fi路由器可能面临的各种问题。我们非常重视Wi-Fi 6，因为它是我们必须跟上的新兴无线技术。Wi-Fi不仅会颠覆我们的通信设备，还会颠覆我们的日常用品，如冰箱、洗衣机、汽车等。但是，无论技术发生多大变化，所讨论的基础知识，如路由、路由表、转发、交换机、集线器等仍然是激动人心的发展背后的关键驱动基本理念，这些发展即将彻底改变我们的生活。
What is a Router and How does it work?
Have you noticed the speed of your internet increaѕe when connected to Wi-Fi opposed to us just using the regυlar 4G network? Well, you gotta thank the Wi-Fi router for that, it makes our browsing experience seamless. Depending on which country you live in, the speed variance could be twice if not more. We are living in a time where the speed of the internet has gone up so much that now we measure our internet speed in Gigabits as opposed to kilobits just a few years ago. It is natural for us to expect improvements in our wireless devices as well with the advent of new exciting technologies that are emerging in the wireless market.
What is a Wi-Fi Router?
In simple words, a Wi-Fi router is nothing but a small box with short antennas that helps transmit the internet throughout your house or office.
A router is a hardware device that acts as a bridge between the modem & the computer. As the name suggests, it routes the traffic between the devices that you use and the internet. Selecting the right type of router plays an important role in determining the fastest internet experience, protection from cyber threats, firewalls, etc.
It is completely fine if you don’t have technical knowledge of how a router works. Let’s understand from a simple example of how a router works.
You might have a wide variety of devices like smartphones, laptops, tablets, printers, smart TVs, and much more that get connected to the internet. These devices together form a network that is called the Local Area Network (LAN). The presence of more & more devices on the LAN results in the consumption of different bandwidths across various devices used, which might result in delays or disruption of the internet in some devices.
This is where the router comes in by enabling the transmission of information across these devices seamlessly by directing the incoming & outgoing traffic the most efficient way possible.
One of the primary functions of a router is to act as a Hub or Switch between computers allowing data assimilation and transfer between them to happen seamlessly.
To process all of these huge amounts of incoming and outgoing data, the router has to be smart, and hence a router is a computer in its own way since it has a CPU & Memory, which helps to deal with incoming & outgoing data.
A typical router performs a variety of complex functions like
- Providing the highest security level from the firewall
- Data transfer between computers or network devices that use the same internet connection
- Enable the use of the internet across multiple devices simultaneously
What are the benefits of a Router?
1. Delivers faster wifi signals
The modern age Wi-Fi routers use layer 3 devices that typically have a range of 2.4 GHz to 5 GHz range that helps in providing faster Wi-Fi signals and extended range than the previous standards.
2. Reliability
A router isolates an affected network and passes the data through other networks that are working perfectly, which makes it a reliable source.
3. Portability
A wireless router eliminates the need for wired connection with the devices by sending Wi-Fi signals, thereby assures the highest degree of portability of a network of connected devices.
There are two different types of routers :
a) Wired router: It connects directly to the computers using cables through a dedicated port that allows the router to distribute information
b) Wireless Router: It is a modern age router that distributes information through antennas wirelessly across multiple devices connected to its local area network.
To understand the working of a router, we need to first look into the components. The basic components of a router include:
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CPU: It is the primary controller of the router that executes the commands of the operating system of the router. It also helps in system initialization, network interface control, etc.
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ROM: The read-only memory contains that bootstrap program & Power on diagnostic programs (POST)
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RAM: The random access memory stores the routing tables and the running configuration files. The contents of the RAM get deleted upon powering the router on and off.
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NVRAM: The non-volatile RAM holds the startup configuration file. Unlike the RAM it stores the content even after the router is switched on and off
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Flash Memory: It stores the images of the operating system and works as a reprogrammable ROM.
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Network Interfaces: The interfaces are the physical connection ports that enable different types of cables to be connected to the router like ethernet, Fiber distributed Data interface (FDDI), integrated services digital network (ISDN), etc.
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Buses: The bus acts as a bridge of communication between the CPU and the interface, which helps in the transfer of the data packets.
What are the functions of a Router?
Routing
One of the primary functions of a router is to forward the data packets through the route specified in the routing table.
It uses certain internal pre-configured directives that are called as the static routes to forward data between incoming and outgoing interface connections.
The router can also use dynamic routing where it forwards the data packets via different routes based on the conditions within the system.
The static routing provides more security to the system compared to dynamic since the routing table does not change unless the user manually changes it.
Recommended: Fix Wireless Router Keeps Disconnecting Or Dropping
Path determination
The routers take into account multiple alternatives to reach the same destination. This is called path determination. The two main factors considered for path determination are:
- The source of information or the routing table
- The cost of taking each path – metric
To determine the optimal path, the router searches the routing table for a network address that completely matches the IP address of the destination packet.
Routing tables
The routing table has a network intelligence layer that directs the router to forward data packets to the destination. It contains the network associations that help the router to reach the destination IP address in the best possible way. The routing table contains the following information:
- Network Id – The destination IP address
- Metric – the path along which the data packet has to be sent.
- Hop – is the gateway through which the data packets have to be sent for reaching the final destination.
Security
The router provides an additional layer of security to the network using a firewall that prevents any type of cybercrime or hacking. A firewall is a specialized software that analyses the incoming data from the packets and protects the network from cyber-attacks.
The routers also provide Virtual Private Network (VPN) that provides an additional security layer to the network and thereby generate a secure connection.
Forwarding table
Forwarding is the actual process of the transmission of the data packets across layers. The routing table helps to select the best possible route while the forwarding table puts the route into action.
How does Routing work?
- The router reads the destination IP address of the incoming data packet
- Based on this incoming data packet, it selects the appropriate path using routing tables.
- The data packets are then forwarded to the final destination IP address through hops using the forwarding table.
In simple words, routing is the process of transmitting the data packets from destination A to destination B using the required information in an optimum way.
Switch
A switch plays a very important role in sharing information across devices that are connected to each other. Switches are generally used for larger networks where all the devices connected together form a Local Area Network (LAN). Unlike a router, the switch sends data packets only to a specific device configured by the user.
We can understand more with a small example :
Let’s say you want to send a photo to your friend on WhatsApp. As soon as you post the picture of your friend, the source & the destination IP address are determined, and the photograph is broken into small bits called the data packets that have to be sent to the final destination.
The router helps to find out the optimum way to transfer these data packets to the destination IP address using routing and forwarding algorithms and manage the traffic across the network. If one route is congested, the router finds all the possible alternative routes to deliver the packets to the destination IP address.
Wi-Fi Routers
Today, we are surrounded by more Wi-Fi access points than any time in history, all of them straining to serve more and more data-hungry devices.
There are so many Wi-Fi signals, strong and weak alike that if we had a special way to see it, there would be a lot of pollution of airspace around.
Now, when we enter a high density & high demand areas such as airports, coffee shops, events, etc. the concentration of multiple users with wireless devices increases. The more people try to get online, the more amount of strain the access point goes through to serve the massive surge in demand. This reduces the bandwidth available to each user and reduces the speed significantly, giving rise to latency issues.
The 802.11 family of Wi-Fi dates back to 1997 and every performance improvements update to Wi-Fi since then has been made in three areas, which has been used as the metric to keep track of the improvement as well and they are
- modulation
- spatial streams
- channel bonding
The modulation is the process of shaping an analog wave to transmit data, just like any audio tune that goes up and down till it reaches our ears (receiver). This particular wave is defined by a frequency where the amplitude & the phase are modified to indicate unique bits of information to the target. So, Stronger the frequency, the better the connectivity, but just like sound, there is only so much we can do to increase the volume if there is interference from other sounds are radio signals in our case, the quality suffers.
Spatial Streams are like having multiple streams of water coming out from the same river source. The river source might be quite strong, but one single stream is not capable of carrying such a high amount of water, so it gets divided into multiple streams to reach the end goal of meeting at the common reserve.
Wi-Fi does these using multiple antennas where multiple streams of data are interacting with the target device at the same time, this is known as MIMO (Multiple Input – Multiple Output)
When this interaction takes place amongst multiple targets, it is known as Multi-User(MU-MIMO), but here is the catch, “the target needs to be sufficiently far away from each other.”
At any given time the network runs on a single channel, Channel Bonding is nothing but combining smaller sub-divisions of a particular frequency to increase the strength between the target devices. The wireless Spectrum is very limited to specific frequencies and channels. Unfortunately, most of the devices run on the same frequency, so even if we increase the channel bonding, there would be other external interferences that would dampen the quality of the signal.
Also Read: How to Find My Router’s IP Address?
What is different about Wi-Fi 6 over its predecessor?
In short has as improved upon speed, reliability, stability, number of connections, and power efficiency.
If we delve deeper into it, we start to notice what makes Wi-Fi 6 so versatile is the addition of 4th metric Airtime Efficiency. All these while, we failed to account for the limited resource that the wireless frequency is. Thus, devices would fill in more channels or frequency than required and be connected far longer than needed, in simple words, a very inefficient mess.
Wi-Fi 6 (802.11 ax) protocol addresses this issue with OFDMA (Orthogonal frequency-division multiple access) where the transmission of data is optimized & combined to only use the required amount of resource requested. This is assigned and controlled by Access Point to deliver the target requested data payload and makes use of Downlink and Uplink MU-MIMO (multi-user, multiple inputs, multiple outputs) to increase the efficiency of data transfer between devices. Utilizing the OFDMA, Wi-Fi devices can send and receive data packets on the local network at higher speeds and at the same time in parallel.
The parallel transfer of data improves the data transferability across the network in an extremely efficient manner without causing a drop in the existing downlink speeds.
What will happen to my old WI-FI devices?
This is a new standard of Wi-Fi set by the International Wi-Fi Alliance in September 2019. Wi-Fi 6 is backward compatible, but there are some cosmetic changes.
Every network that we connect to runs on a different speed, latency, and bandwidth denoted by a certain letter after 802.11, such as 802.11b, 802.11a, 802.11g, 802.11n and 802.11ac which has baffled even the best of us.
All of this confusion got put to an end with Wi-Fi 6, and the Wi-Fi alliance changed the naming convention with this one. Every Wi-Fi version before this will be numbered between Wi-Fi 1-5 for the ease of expression.
Conclusion
Having a good understanding of a router’s works helps us to navigate and solve various issues we may face with our routers as well as Wi-Fi routers. We have put a lot of emphasis on Wi-Fi 6, as it is a new emerging wireless technology that we have to keep up with. Wi-Fi is about to disrupt not just our communication devices but also our day-to-day items like refrigerators, washing machines, cars, etc. But, no matter how much the technology changes, the fundamentals discussed, such as routing, routing tables, forwarding, switches, hubs, etc. still are the critical driving fundamental idea behind the exciting developments that are about to change our lives entirely for good.
