使用您的家庭网络就像输入密码并打开您的Netflix App 观看电影一样简单，但您的网络及其无缝工作所需的一切可能是您拥有的最复杂和最独特的设备。
家庭(Home)网络的存在是为了让数字设备通过称为互联网的全球网络相互通信并与世界上的其他设备通信。虽然您不需要准确了解家庭网络的功能来享受它，但花一些时间在引擎盖下既可以让您欣赏技术，又可以更轻松地解决出现的问题。
您的家庭网络(Network)是一个迷你互联网(Mini Internet)
Internet 是“internetwork”的缩写，它是连接LAN(LANs)（局域网(Local Area Networks)）的全球网络，包括 Web 服务器、流媒体和云服务、游戏服务器等等。
您的家庭网络也是一样的，只是更小并且仅限于您的家。如果您想更多地了解您的家庭网络如何像一个迷你互联网，请查看谁拥有互联网？Web Architecture Explained(Who Owns the Internet? Web Architecture Explained)(Who Owns the Internet? Web Architecture Explained)对复杂的互联网机器进行了简单的解释。
您的家庭网络讲(Home Network Speaks)一种特殊的语言
除了物理上与整个互联网相似之外，您的家庭网络和互联网相同的另一个关键方式是它们所说的“语言”。今天的通用网络协议是TCP/IP（Transmission Control Protocol/Internet Protocol），它是使数据到达预期位置的关键。
在TCP/IP网络中，通过网络发送的所有数据都被分解为“数据包”。” 想象一下(” Imagine)，将一张图片变成一个包含数千块的拼图游戏。然后取出每一块，分别放入信封中。在信封上写上寄件人和收件人的地址。还包括每个信封中的信息，描述每个部分去哪里重建原始图像。
现在，将数千个信封邮寄给收件人，他们最终会重建它。信封到达时是否乱序并不重要，但如果有任何信封丢失，您会收到回信，要求提供丢失的信封的新副本。
基本家庭网络拓扑
我们将在下面详细解释每个网络组件的工作，但为了帮助您了解方向，让我们勾勒出当今典型的家庭网络的样子。
您的网络有几个关键组件：
- 调制解调器将您连接到WAN（互联网(Internet)）
- 路由器管理LAN上的设备之间以及这些设备与WAN之间的流量。
- 网络硬件连接，通常是以太网电缆或 Wi-Fi 无线电发射器和接收器。
- 客户端设备，例如计算机或Android和 iOS 智能手机。
- 服务器(Server)设备，也可以是计算机和智能手机等设备。
- 可选(Optional)的网络扩展器，有助于将网络的物理足迹扩展到您的家中。示例(Examples)包括无线接入点、电力线(Powerline)扩展器和 Wi-Fi 中继器。
构建家庭网络有许多不同的方法，但这些组件中的大多数都存在于每个家庭网络中。其他组件可以代替其中的一些。例如，如果您只是想将一组计算机联网，您可以使用以太网(Ethernet)交换机或网络集线器。然而，这个基本草图涵盖了 99% 的内容。
既然我们已经勾勒出家庭网络的粗略轮廓，我们将更深入地研究每个主要组件。
调制解调器让(Modem Lets)您与互联网(Internet)交谈
在现代宽带互联网之前，互联网接入通过调制解调器（调制器/解调器）工作，该调制解调器通过铜语音线发送和接收高音或低音音频信号，代表二进制代码。
这些“拨号”调制解调器现在几乎已经过时，并且不能提供太多带宽，尽管它们仍然在少数情况下使用，因为它们是不可能的。如今，调制解调器一词用于指代几乎任何将一种网络信号转换为另一种网络信号的设备，即使这两种信号实际上都是数字信号。
数字到数字转换的一个例子是普通光纤调制解调器，它接收光信号并通过以太网(Ethernet)电缆输出电脉冲。DSL调制解调器使用与电话线相同的铜线，但使用与语音通话不同的频段，因此您可以连接到互联网并同时拨打电话。蜂窝调制解调器通过无线电波连接到手机信号塔——卫星调制解调器将信息传送到轨道或从轨道传送，等等。
在某些网络中，调制解调器是一个单独的设备，而在其他网络中，它与您的无线路由器相结合，这恰好是我们这次家庭网络之旅的下一站。
路由器(Router Sits)位于网络(Your Network)的核心(Heart)_
路由器是任何家庭网络的核心，并执行广泛的基本工作：
- 在设备之间、以太网(Ethernet)和LAN之间以及内部和外部网络之间路由网络流量。
- DNS（域名服务(Domain Name Service)）服务器检测和路由。
- 内部类似于具有CPU、RAM和 OS 的计算机。一些路由器可以运行应用程序。
- (Assigns)使用DHCP（动态主机配置协议(Dynamic Host Configuration Protocol)）在LAN上(LAN)分配和管理 IP 地址。
除了这些核心功能之外，路由器还有更多的功能，但这是路由器所做事情的关键列表。不同类型的网络（光纤WAN、以太网(Ethernet)、Wi-Fi等）之间的路由是使路由器成为路由器的原因，将其与(Wi-Fi)网络交换机和集线器(network switches and hubs)区分开来。
路由器将 IP 地址分配给内部网络设备，确保没有冲突。它在称为NAT(NAT)（网络地址表(Network Address Table)）的表中跟踪哪个设备向 Internet 上的设备发出哪个请求，因为 Internet 上的服务器只能看到路由器本身及其“公共”IP 地址。
一些高端路由器可以运行自定义应用程序来充当网络存储或流服务器。即使您的路由器不具备此功能，您也可以选择安装自定义第三方固件来添加这些功能。
您的本地服务器
服务器(server )是网络上提供服务的设备，例如内容或基于网络的应用程序。当您访问网站或从 Internet 下载文件时，该内容托管在世界某处的服务器计算机上。当您使用Google Docs等云应用程序时，该软件和数据位于服务器上。
您的本地网络至少有一台服务器，那就是您的路由器。每个路由器都有一个基本的 Web 服务器，作为更改设置的接口。当您连接到路由器并在浏览器中输入其 IP 地址时，您将被带到由路由器本身托管的网站。
如果您有Wi-Fi 打印机(Wi-Fi printer)，那也是处理打印请求的打印服务器。许多人在他们的网络上运行NAS（网络附加存储(Network-attached storage)设备）或媒体服务器（例如Plex）。您可能不认为服务器的某些事情也符合条件。您的 IP 摄像机也是一个服务器。这是一个视频流服务器！
联网外设
传统上，扫描仪和打印机等外围设备直接连接到特定的计算机。但是，在现代家庭中，拥有许多需要访问这些类型设备的不同计算机的情况要普遍得多。您可以在本地网络上共享一台打印机，而不是让每个人在需要打印时都使用同一台计算机。
使用计算机操作系统中的打印共享功能，可以将连接到计算机的普通打印机用作共享打印机。尽管如此，现在很容易购买带有Wi-Fi或以太网的打印机、扫描仪或多功能设备 ( (Ethernet)MFD )，并将其作为网络上的独立共享资源。
您家中的网络客户端
除了家庭网络上的本地服务器外，其他设备通常称为客户端，它们从远程和本地服务器中提取信息。本地网络客户端的示例包括：
- 计算机、控制台和移动设备。
- (Internet)物联网( IoT ) 设备，(Things)例如(IoT)智能冰箱和机器人吸尘器。
任何从服务器设备接收数据的东西都是客户端，尽管任何设备都可以同时是两者。
计算机、控制台(Consoles)和移动(Mobile)设备
有线和无线连接
多年来，网络出现了几种不同的连接标准，但在当今几乎每个家庭网络中，您只会发现两种类型的连接：以太网和Wi-Fi。
不要让你的(Get Your)电线交叉：以太网
以太网(Ethernet)是一种有线连接标准，可在家庭网络中TCP/IP连接器 ( RJ45 ) 看起来有点像大型电话线连接 ( RJ11 )，并带有几根铜线，这些铜线根据您使用的以太网网络电缆的类别而有所不同。(Ethernet)
以太网电缆分为不同的类别，提供不同的最大速度。例如，6 类(Category 6)网络电缆的额定速度为 10Gbps，而5e 类(Category 5e)电缆的额定速度为千兆。将电缆类型与LAN 端口(Ports)的额定速度相匹配非常重要。将 1Gbps 电缆插入 100 Mbps端口不会受到伤害，但反之则将您的速度限制在电缆可以处理的最大速度！
假设您选择了正确的以太网(Ethernet)电缆、适配器和路由器，您将享受高速、低延迟、超可靠的网络速度，只要您可以在家里安装以太网连接的麻烦。
电线？我们要去哪里(Going)，我们不需要电线：Wi-Fi
虽然以太网(Ethernet)无疑是纯网络性能的黄金标准，但它并不是那么方便。当涉及到移动设备时，这是完全不切实际的！这就是为什么我们有Wi-Fi（无线保真(Wireless Fidelity)）来允许无线设备以一种方式连接到网络，而无需在每次需要网络功能时在墙上钻孔或插入它们。
Wi-Fi使用无线电波发送信息的数字脉冲。Wi-Fi中使用了两个频段：2.4Ghz 和 5Ghz。较低的频段不能高速发送数据，但它有很大的范围和穿墙能力。高频 5Ghz Wi-Fi速度超快，但很容易被(blocked by objects)墙壁等物体阻挡。
大多数现代Wi-Fi路由器都是“双频”路由器，这意味着它们在两个频段上都提供连接。Wi-Fi分为几代。过去，这些代的名称会反映该代Wi-Fi的通信标准名称。例如，802.11g、802.11n 和 802.11ac。这些名称已更改为简单的数字，以使事情更加用户友好。所以现在 802.11ac 就是Wi-Fi 6，最新的 802.11ax 就是Wi-Fi 6。
较旧的 Wi-Fi 设备可能无法连接到较新的路由器，特别是如果该设备仅支持 2.4Ghz Wi-Fi 而相关路由器仅提供 5Ghz。
扩展您的网络范围
有这么多设备，无论是现在还是未来，都可以连接到您的家庭网络，您可能希望确保网络延伸到您家的每个角落。说起来容易做起来难，因为一切可能会阻止无线信号或在整个家庭中铺设以太网的费用和努力。(Ethernet)
好消息是市场上有许多产品可以帮助您增加网络覆盖范围，这样您家中就没有任何无法连接的地方。
Wi-Fi 中继器和扩展器(Wi-Fi Repeaters and Extenders)
Wi-Fi中继器是一种在Wi-Fi信号开始下降之前放置在现有Wi-Fi网络边缘的设备。(Wi-Fi)它侦听进出核心Wi-Fi网络的数据包，然后简单地重复它们。这是一个缓慢的解决方案，但却是一种无需修改网络即可将WiFi(WiFi)扩展到特定地点的简单方法。
电力线延长器
该系统通过您家中现有的电线发送网络信号。就像在路由器附近和要扩展网络的房间中插入PowerLine适配器一样简单。(PowerLine)
无线网状路由器不会扩大您常规路由器的占地面积，而是完全取代您现有的路由器。将(Think)它们视为一个大型分布式路由器。一个主网状单元连接到您的调制解调器，然后每个卫星单元都有一个专用的无线或有线连接。
一个网络大家庭
您的家庭网络中的技术可能非常复杂，但随着时间的推移，这项技术已经变得更智能且更易于使用。没有人知道家庭网络的未来会是什么。尽管如此，由于毫米波 5G 蜂窝网络等技术的发展，它可能看起来非常不同，这些技术模糊了本地网络和广泛网络之间的界限。
A Quick Guide to How Your Home Network Works
Using your home netwоrk is as easy as typing in a password and opening your Netflix app to watch а movie, but yoυr network and everything that’s needed for it to work so seamlesslу are probably the most complex and unique devices you own.
Home networks exist to let digital devices talk to each other and to other devices out in the world over a global network called the internet. While you don’t need to understand precisely how your home network functions to enjoy it, spending some time under the hood will both give you an appreciation for the tech and make troubleshooting problems that come along easier.
Your Home Network Is a Mini Internet
The internet is short for ‘internetwork’, a global network of connected LANs (Local Area Networks) that includes web servers, streaming and cloud services, gaming servers, and much more.
Your home network is the same thing, but just smaller and confined to your home.If you want to know more about how your home network is like a mini internet, check out Who Owns the Internet? Web Architecture Explained for a straightforward explanation of the complex machine that is the internet.
Your Home Network Speaks a Special Language
Apart from physically resembling the internet as a whole, another critical way your home network and the internet are the same is the “language” they speak. Today the universal network protocol is TCP/IP (Transmission Control Protocol/Internet Protocol), and it’s key to making data go where it’s supposed to.
In a TCP/IP network, all data sent over the network is broken up into “packets.” Imagine turning a picture into a jigsaw puzzle with thousands of pieces. Then take each piece and put it in an envelope individually. On the envelope, write the address of the sender and the receiver. Also include information in each envelope describing where each piece goes to reconstruct the original image.
Now, mail thousands of envelopes to the recipient, and they rebuild it on their end. It doesn’t matter if the envelopes arrive out of order, but if any go missing, you’ll get letters back asking for new copies of the missing pieces.
Basic Home Network Topography
We’ll explain the job of each network component in detail below, but to help you get oriented, let’s sketch out what a typical home network looks like today.
Your network has several key components:
- The modem connects you to the WAN (Internet)
- The router manages traffic between devices on the LAN and between those devices and the WAN.
- The network hardware connections, usually ethernet cables or Wi-Fi radio transmitters and receivers.
- Client devices, like computers or Android and iOS smartphones.
- Server devices, which can also be equipment like computers and smartphones.
- Optional network extenders, which help spread your network’s physical footprint through your home. Examples include wireless access points, Powerline extenders, and Wi-Fi repeaters.
There are many different ways to build a home network, but most of these components are present in every home network. Other components can stand-in for some of these. For example, if you simply wanted to network a group of computers together, you could use an Ethernet switch or network hub. However, this basic sketch covers 99% of what’s out there.
Now that we’ve drawn the rough outlines of a home network, we’ll dive a little deeper into every major component.
The Modem Lets You Talk to the Internet
Before modern broadband internet, internet access worked through a modem (modulator/demodulator) which sent and received high- or low- pitched audio signals over copper voice lines, representing binary code.
These “dial-up” modems are all but obsolete now and do not provide much bandwidth, although they are still used in a few rare cases where nothing else is possible. These days the word modem is used to refer to just about any device that converts one kind of network signal to another, even if both signals are, in fact, digital.
One example of digital-to-digital conversion is the common fiber modem, which takes optical signals and puts out electrical pulses over Ethernet cables. DSL modems use the same copper wire as phone lines but use a different frequency band from voice calls, so you can connect to the internet and make calls simultaneously. Cellular modems connect to cell phone towers via radio waves—satellite modems beam information to and from orbit, and so on.
In some networks, the modem is a separate device, and in others, it’s combined with your wireless router, which happens to be our next stop on this home network tour.
The Router Sits at the Heart of Your Network
The router is at the heart of any home network and performs a wide range of essential jobs:
- Routing network traffic between devices, between Ethernet and LAN, and between internal and external networks.
- DNS (Domain Name Service) server detection and routing.
- Is internally similar to a computer with CPU, RAM, and OS. Some routers can run apps.
- Assigns and manages IP addresses on the LAN using DHCP (Dynamic Host Configuration Protocol).
There’s more to routers than these core functions, but that’s the key list of things a router does. Routing between different types of networks (fiber WAN, Ethernet, Wi-Fi, etc.) is what makes a router a router, setting it apart from network switches and hubs.
The router assigns IP addresses to internal network devices, making sure that there are no conflicts. It keeps track of which device makes which request of devices on the internet in a table known as a NAT (Network Address Table), since servers on the internet can only see the router itself and its “public” IP address.
Some high-end routers can run custom applications to act as network storage or streaming servers. Even if your router doesn’t ship with this ability, you may have the option of installing custom third-party firmware to add those features.
Your Local Servers
A server is a device on a network that offers a service such as content or network-based applications. When you visit a website or download a file from the internet, that content is hosted on a server computer somewhere out in the world. When you use cloud apps like Google Docs, that software and data live on a server.
Your local network has at least one server, and that’s your router. Every router has a basic web server that acts as an interface to change settings. When you’re connected to the router and type in its IP address in a browser, you’re taken to a website that’s hosted by the router itself.
If you have a Wi-Fi printer, that’s also a print server that handles print requests. Many people have NAS (Network-attached storage devices) or media servers (such as Plex) running on their network. Some things you might not think of as servers also qualify. Your IP camera is also a server. It’s a video streaming server!
Networked Peripherals
Traditionally peripherals like scanners and printers are connected directly to a specific computer. However, it’s far more common in a modern household to have many different computers that need access to these types of devices. You can share a printer on the local network rather than having everyone use the same computer whenever they need to print something.
Using the print sharing feature in the computer’s operating system makes it possible to use a normal printer connected to a computer as a shared printer. Still, these days it’s easy to simply buy a printer, scanner, or multifunction device (MFD) with Wi-Fi or Ethernet and have it act as a standalone shared resource on the network.
Network Clients in Your Home
Apart from local servers on your home network, the other devices are generally known as clients, which pull information from remote and local servers. Examples of local network clients include:
- Computers, consoles, and mobile devices.
- Internet of Things (IoT) devices such as smart fridges and robot vacuum cleaners.
Anything that receives data from a server device is a client, although any device can be both at the same time.
Computers, Consoles, and Mobile Devices
Wired and Wireless Connections
There have been a few different connection standards for networks over the years, but in almost every home network today, you’ll find just two types of connection: Ethernet and Wi-Fi.
Don’t Get Your Wires Crossed: Ethernet
Ethernet is a wired connection standard that carries TCP/IP data in-home networks. The connector (RJ45) looks a little like an upsized telephone line connection (RJ11) and carries several copper wires that vary depending on the category of Ethernet network cable you’re using.
Ethernet cables are classed into different categories that offer different maximum speeds. For example, Category 6 network cables are rated 10Gbps, while Category 5e cables are rated for gigabit speeds. It’s important to match your cable types to the speed your LAN Ports are rated for. Plugging a 1Gbps cable into a 100 Mbps port won’t hurt, but doing the opposite will limit your speed to the maximum the cable can handle!
Assuming you’ve chosen the right Ethernet cables, adapters, and router, you’ll enjoy high-speed, low-latency, ultra-reliable network speeds as long as you’re okay with the hassle of installing ethernet connections throughout your house.
Wires? Where We’re Going, We Don’t Need Wires: Wi-Fi
While Ethernet is undoubtedly the gold standard when it comes to pure network performance, it’s not all that convenient. When it comes to mobile devices, it’s downright unpractical! That’s why we have Wi-Fi (Wireless Fidelity) to allow wireless devices a way to connect to the network without drilling holes in walls or plugging them in every time we need network features.
Wi-Fi uses radio waves to send digital pulses of information. There are two frequency bands used in Wi-Fi: 2.4Ghz and 5Ghz. The lower frequency band can’t send data at high speeds, but it’s got great range and wall-penetrating power. High-frequency 5Ghz Wi-Fi is ultra-fast but is easily blocked by objects like walls.
Most modern Wi-Fi routers are “dual-band,” which means they offer connections on both frequency bands. Wi-Fi is divided into generations. In the past, those generations would have numbered names reflecting the name of the communication standard for that generation of Wi-Fi. For example, 802.11g, 802.11n, and 802.11ac. These names have been changed to simple numbers to make things a little more user-friendly. So now 802.11ac is simply Wi-Fi 6, and the latest 802.11ax is Wi-Fi 6.
Older Wi-Fi devices may not connect to newer routers, especially if the device only supports 2.4Ghz Wi-Fi and the router in question only offers 5Ghz.
Extending Your Network’s Reach
With so many devices, both present and future-looking, for a way to connect to your home network, you probably want to make sure that network stretches to every corner of your home. That’s easier said than done with everything that can block a wireless signal or the expense and effort of laying Ethernet throughout a home.
The good news is that there are many products on the market to help you increase your network footprint so that there aren’t any spots in your home that can’t get connected.
A Wi-Fi repeater is a device that’s put onto the edge of an existing Wi-Fi network before the Wi-Fi signal starts to drop off. It listens to the packets coming to and from the core Wi-Fi network and then simply repeats them. This is a slow solution, but a simple way to extend WiFi to specific spots without modifying your network.
PowerLine Extenders
This system sends network signals through the existing electrical wiring in your home. It’s as easy as plugging in a PowerLine adapter near your router and in the room where you want to extend your network.
Rather than extend your regular router’s footprint, wireless mesh routers completely replace your existing router. Think of them as one big distributed router. A primary mesh unit is connected to your modem, and then each satellite unit has a dedicated wireless or wired connection to it.
One Big Networked Family
The technology in your home network might be incredibly complex, but this technology has become smarter and much easier to use over time. No one knows what the future of home networking will be. Still, it might look very different thanks to the development of technologies like millimeter-wave 5G cellular networks, which blur the line between local and wide networks.
