How a router for dummies works. How to choose a router: everything you can and cannot save on

So, have you decided to make a local network at home? Or do you have devices such as your phone, laptop, tablet and computer that you would like to keep online all the time? Nothing could be easier!

Why do I even need this router of yours?

Today, almost everyone has the Internet. This is not just an opportunity to listen to music or play games, it is already a necessity. Look: they're starting things up in schools electronic diaries, at work, documents are sent by email, and so on. Therefore, the Internet is no longer a fad and entertainment, but the main means of communication is probably even more important cell phone. Well, I’ve convinced you that you need the Internet, and everywhere: on your computer, on your laptop, and even on your computer.

How can you divide it in such a way as to connect all devices, because there is only 1 cable and it only fits the computer’s network card (Ethernet port). And the answer is very simple - buy a WiFi router and connect all the devices you need over the air. All the advantages here are obvious - no wires, you can connect at least 10 or 20 devices at the same time. But how does a router work?

How the router works in simple terms

In fact, router is a misnomer for the Russian language. This device is called a router in English, but in Russian it is a Router, such things. So how does it work?

Let's look at the picture and understand. In simple words, it turns out like this: an Internet cable comes into your apartment. In some cases, this cable must first be connected to a modem (depending on the provider), and the modem will already process the signal, and the output will be the same Internet. You have a choice - connect it to your computer and gain access to the network only on it, or connect this cable to a router, which will distribute access to all your devices. The computer can be connected to the router with a separate piece of cable (crimped on both sides, of course), and devices with a WiFi receiver can be connected over the air. Most routers are already configured as needed from the factory and you only need to set a password to access your WiFi network.

How a router works (a slightly more complex explanation)

The internal organization of the device is as follows: it stores a routing table in its memory, which contains paths to all devices on the network, as well as to other routers. The result is such a connected network of devices, to each of which you can choose the most optimal and shortest path. The router periodically sends test packets to each address to find out the time it will take for the packet to arrive and whether it will arrive at all (the device may have turned off). Thus, it always maintains an up-to-date state of the network map using its routing table.

BUT here it should be clarified that this refers to dynamic routing, which is very effective and convenient. However, there are times when you need to hardcode the addresses of all devices on the network so that packets do not suddenly go to the wrong place, for example to attackers. Then static routing is used, which, although it takes a lot of time and effort, especially if the network is large, is safer. There are just some ways, the guys and I at the university tested this in practice, when you can fill the router’s memory and set the paths for the packets that you need. This is one of the ways to intercept packets on a network - to mislead the “distributor,” that is, the router.

So now you know approximately how the router works and you can explain it both in simple language and in a slightly more complex language, for example, to a computer science teacher at school, he still doesn’t know, so if you confidently tell him this, then he will believe.

Typically, to create a simple local area network (computer network) built on Ethernet or Wi-Fi technology, a network device (router, modem, switch, wireless access point...) is used. But out of all this diversity network devices we are interested in the router. So why do you need a router and what role does it play in the local network?

Router- this is a network computer connecting sections of the local network, which processes the received data according to the specified rules of the administrator and, based on the routing table, determines the path for sending data.

To make it more clear, let's look at the router's participation in the home local network. Suppose you have at home desktop computer(desktop), laptop (laptop), printer or MFP (Multifunctional Device), tablet and in addition you want to buy a Smart TV with 3D. Only one LAN cable comes into your apartment through which the provider provides you with access to the Internet. The question arises: “How to simultaneously give all devices access to the Internet if there is only one cable from the provider in the apartment?”

This is where a wireless router comes to the rescue, which can be connected to the provider’s cable (top image) and give all devices (Smart TV, computer, tablet...) access to the Internet. If the provider uses telephone lines, then the router is connected to the Internet via a modem (lower image). The connection between home devices and the wireless router is carried out via a LAN cable (twisted pair cable crimping without tools) and via wireless Wi-Fi networks(examples of a weak Wi-Fi signal).

The principle of operation of the router.

In this way, the router connects disparate network segments (local home network and global Internet) and, based on the routing table, sends data to the recipient.

Routing table- this is an electronic database in the router, which is a certain set of rules. It contains information about network routes along which the best path for transmitting a data packet is determined.

The table contains the destination network address and mask, the gateway address (the router on the network to which data is sent), the metric (distance) and the interface (device name or identifier).

It should be said that a router, unlike a switch, cannot create a table based on information from received packets. It is stored in its memory and can be created dynamically or statically.

Through special protocols, the router periodically sends test information to each address and uses the received data to maintain the actual network map. In other words, routers periodically scan the network and exchange information about each other and the network to which they are connected. This process is called dynamic routing.

Static routing involves manual creation of a table by the administrator. In this case, all routing is performed without the participation of special protocols.

In contrast to a switch (Switch/OSI Layer 2/"Link") and a hub (Hub/OSI Layer 1/"Physical"), a router stands head and shoulders above, as it operates at the third layer of the OSI model (base reference model) , which is called "Network".

The most common types of Ethernet technologies

Overview of modern local networksEthernet

Ethernet(Ethernet, from Latin aether - ether) - packet technology of computer networks.

Ethernet is the most popular family of standards for local area networks worldwide, which covers the physical and data link layers of the OSI model. Ethernet standards differ in the speed they support; Speeds of 10, 100 and 1000 Mbit/s (i.e. 1 Gbit/s) are widely used today. Different technology variants also differ in the type of transmission medium used, for example, the most popular Ethernet standards use an inexpensive type of cable, namely Unshielded Twisted Pair UTP, while others use more expensive fiber optic cable. The use of fiber optic cable is justified if you need to connect devices that are located at a large distance from each other, or in case of increased requirements for network security. To meet various needs when creating local networks, various standards have been developed that work on different speeds, different types of data transmission media (the greater the distance, the more expensive the technology), etc. The Institute of Electrical and Electronics Engineers (IEEE) has published many Ethernet standards since it led the charge in standardizing local area networks in the early 1980s. Most standards are implemented differently at the physical layer, working with different speeds and cable types.

In IEEE standards, the link layer is divided into two sublayers:

IEEE 802.3 media access control sublayer

(MAC sublayer);

 IEEE 802.2 logical channel control sublayer (LLC sublayer).

In fact, the MAC address gets its name from the name of the lower sublayer of the Ethernet data link layer. Each new physical layer standard published by IEEE contains many differences from its predecessors, but still uses the same 802.3 header format and the LLC sublayer as the top layer.

In table 3.2 lists the most commonly used IEEE Ethernet standards

for the physical level.

Table 3.2. The most common types of Ethernet technology

It is common knowledge e name	Speed	Alternative Name	Standard	Cable type, maximum length (m)
				Copper, 100
				Copper, 100
Gigabit Ethernet				Optical, 550 for SX, 5000 for LX
Gigabit Ethernet				Copper, 100

Application layer. The upper (7th) level of the model ensures interaction between the network and the user. The layer allows user applications to access network services such as database query handler, file access, forwarding Email. It is also responsible for transmitting service information, providing applications with information about errors, and generating requests to the presentation layer. Example: HTTP, POP3, SMTP.

Presentation layer. Layer 6 is responsible for protocol conversion and data encoding/decoding. It converts application requests received from the application layer into a format for transmission over the network, and converts data received from the network into a format that applications can understand. The presentation layer can perform compression/decompression or encoding/decoding of data, as well as redirecting requests to another network resource, if they cannot be processed locally.

Session layer. Level 5 of the model is responsible for maintaining a communication session, which allows applications to interact with each other for a long time. The session layer manages session creation/termination, information exchange, task synchronization, determination of data transfer rights, and session maintenance during periods of application inactivity. Transmission synchronization is ensured by placing checkpoints in the data stream, from which the process is resumed if interaction is disrupted.

Transport layer. The 4th level of the model is designed to deliver data without errors, losses and duplication in the sequence in which they were transmitted. It does not matter what data is transmitted, from where and where, that is, it provides the transmission mechanism itself. It divides data blocks into fragments, the size of which depends on the protocol, combines short ones into one, and splits long ones. Protocols at this level are designed for point-to-point communication. Example: TCP, UDP

Network layer. Layer 3 of the OSI network model is designed to determine the data transmission path. Responsible for translating logical addresses and names into physical ones, determining the shortest routes, switching and routing, monitoring problems and congestion in the network. A network device such as a router operates at this level.

Data Link layer. This layer is designed to ensure the interaction of networks at the physical layer and control errors that may occur. It packs the data received from the physical layer into frames, checks for integrity, corrects errors if necessary, and sends it to the network layer. The data link layer can communicate with one or more physical layers, monitoring and managing this interaction. The IEEE 802 specification divides this layer into 2 sublayers - MAC (Media Access Control) regulates access to the shared physical medium, LLC (Logical Link Control) provides network layer service. Switches and bridges operate at this level. In programming, this level represents the network card driver; in operating systems there is a software interface for the interaction of the channel and network layers with each other; this is not a new level, but simply an implementation of the model for a specific OS. Examples of such interfaces: ODI, NDIS

Physical layer. The lowest level of the model is intended directly for transmitting the data stream. Transmits electrical or optical signals into a cable or radio broadcast and, accordingly, receives them and converts them into data bits in accordance with coding methods digital signals. In other words, it provides an interface between the network media and the network device. At this level, signal concentrators (hubs), signal repeaters (repeaters) and media converters operate. Physical layer functions are implemented on all devices connected to the network. On the computer side, the physical layer functions are performed network adapter or serial port.

The TCP/IP protocol is mainly used

Definition:

Transmission Control Protocol/Internet Protocol, TCP/IP(Transmission Control Protocol/Internet Protocol)

Most network server and workstation operating systems support TCP/IP, including NetWare servers, all Windows systems, UNIX, latest versions Mac OS, IBM's OpenMVS and z/OS systems, and DEC's OpenVMS. In addition, network equipment manufacturers create their own system software for TCP/IP, including tools to improve device performance. The TCP/IP stack was originally used on UNIX systems and then quickly spread to many other types of networks.

Local network protocols

Properties of local network protocols

In general, local area network protocols have the same properties as other communication protocols, but some of them were developed long ago, during the creation of the first networks, which were slow, unreliable, and more susceptible to electromagnetic and radio interference. Therefore, some protocols are not entirely suitable for modern communications. Disadvantages of such protocols include poor error protection or excessive network traffic. In addition, certain protocols were created for small local networks and long before the advent of modern corporate networks with advanced routing capabilities.

Local network protocols must have the following basic characteristics:

ensure the reliability of network channels;

have high performance;

process source and destination node addresses;

Comply with network standards, especially IEEE 802.

In general, all the protocols discussed in this chapter meet these requirements, but, as you will learn later, some protocols have more capabilities than others.

The table lists the local network protocols and the operating systems with which these protocols can work. Later in the chapter, protocols and systems (in particular, server operating systems and host computers) will be described in more detail.

Table Local network protocols and network operating systems

Protocol	Corresponding Operating System

	First versions of operating systems Microsoft systems Windows
	Apple Macintosh
	UNIX, Novel NetWare, modern versions of operating systems Microsoft Windows, IBM mainframe operating systems
	IBM mainframe and minicomputer operating systems
	Client systems interacting with IBM mainframes configured to work with the SNA protocol

Internet protocol concept

It is obvious that sooner or later computers located in different parts of the globe, as their number increased, had to acquire some means of communication. Computer networks became such means. Networks are local and global. The local network is a network that connects computers geographically located a short distance from each other - for example, in the same building. Global networks serve to connect networks and computers that are separated by long distances - hundreds and thousands of kilometers. The Internet belongs to the class of global networks.

Simply connecting one computer to another is a necessary step to create a network, but not sufficient. To start transmitting information, you need to make sure that computers “understand” each other. How do computers “communicate” over a network? To provide this possibility, special tools called “protocols” were developed. A protocol is a set of rules according to which information is transmitted through a network. The concept of a protocol is not only applicable to the computer industry. Even those who have never dealt with the Internet have most likely worked in everyday life with some devices whose functioning is based on the use of protocols. Thus, a regular public telephone network also has its own protocol, which allows devices, for example, to establish that the handset has been picked up at the other end of the line or to recognize a disconnection signal and even the caller’s number.

Based on this natural need, the world of computers needed a single language (that is, a protocol) that would be understandable to each of them.

The main protocols used in the Internet:

Today, most devices are equipped with specialized radio modules, which, using Wi-Fi technology can communicate with various other devices. But the main purpose of this module is to access the Internet at high speed.

Despite the development modern technologies, providers still provide Internet via wired technology. That is why wired routers have been replaced by routers using Wi-Fi technology. These devices provide simultaneous access to one Internet channel for multiple devices.

Router Definition

A router (or router) is essentially a kind of mini computer. It performs the function of distributing Internet channel resources. The coverage area of a Wi-Fi router can be very different, it all depends on the model and its type.

The router is used as an access point, which performs the following functions:

forwarding data packets between individual segments of the same network;
connects different networks to each other (each network may have its own architecture);
can forward various information based on the topology of the network architecture.

There are some similarities between a router and a hub. It lies in the different network layers at which these two devices operate. The router operates on the 3rd network model called OSI. The hub operates on the 1st level or on the 2nd.

Purpose of the router

A Wi-Fi router is designed to organize network space. Moreover, it is used not only as a bridge to create a connection between an Internet provider and various network devices, but also as a connecting link between various local network devices.

There are three main purposes of a Wi-Fi router:

How the router works

The operating principle of all routers is the most different types(portable, home, wired and wireless) is practically the same. It consists of finding, using a special table contained in the router’s memory, the address of the recipient of the transmitted data. If the required addressee is missing, the packet is simply not processed and is reset.

The routing table looks something like this:

Information can also be transmitted in some other ways, using:

sender's address;
protocols of various levels;
contents of network packet headers;
various other information.

Many routers can perform the following operations:

broadcast addresses of both recipient and sender;
filter the transit data stream;
encrypt and decrypt data.

Review of routers

There are many models of routers of different types.

Conventionally, all of them can be divided into the following categories:

Routers are also divided by connection type:

A home router is the most common hub option. This network equipment has slightly larger overall dimensions than other types (internal, mini and automotive).

But they have a number of advantages over their counterparts:

large coverage area;
ease of setup;
ease of use.

An excellent home router model with a compromise price is the TP-Link TL-WR841N. Its operation is quite stable and the cost is low.

Photo: optimal price-quality ratio

Car routers are the smallest of all varieties. They are extremely compact in size. Also, quite often, manufacturers equip it with a shockproof housing. The disadvantages include a small coverage area. Power is usually supplied from car wiring - where a voltage of 12 (V) is present.

One of the most common models of 3G routers is the UMTS ZTE MF60. It is compact and holds a battery charge for quite a long time.

Mini-routers have very modest overall dimensions. They allow it to be used even in places where the amount free space very limited. This type of network device is also sometimes called a pocket Wi-Fi router.

Routers for TV are highly specialized equipment designed to connect to a TV. Used with various models, which are equipped with the ability to connect to the Internet.

3G Wi-Fi routers are hubs that have the ability to connect to a cellular network using 3G technology. They are equipped with a special radio module that allows communication through a regular SIM card of a cellular operator. One of the most popular routers of this type is the H25A 3G WiFi.

External Wi-Fi routers are all routers located outside of a personal computer. Internal routers are usually small boards that fit inside system unit personal computer. In terms of functionality, they are practically the same. In some cases, internal routers are more convenient because they can be easily placed inside the case. And they don't take up space on your desk or anywhere else.

Routers cannot be globally different from each other in any way. The operation of all devices is based on the same principle.

Router cost table

Routers are divided into different categories not only by type, but also by cost. This makes choosing the right model much easier - you can easily choose either a very expensive model with many additional features or the cheapest one.

Functions and characteristics of routers

To work comfortably at home or in the office, you need a Wi-Fi router that can support a fairly wide channel and also have good performance characteristics:

One of the most important characteristics of routers is support for standards such as IEEE 802.11g, IEEE 802.11n. In the first case, data exchange is possible at a speed of 54 Mbit/s through the gateway, in the second case – up to 600 Mbit/s;
It is desirable to have a USB port and the ability to use 3G technology to connect to the Internet. This will make it possible to avoid having large quantity various wires underfoot;
It is desirable that the router supports protocols such as L2TP and PPTP. Otherwise, working with some Internet providers will simply be impossible (for example, with Beeline).

Video: review of Wi-Fi router “Upvel UR-309BN”

Features and differences of routers

A Wi-Fi router has many features:

Most models have the ability to connect not only Wi-Fi assistance, but also using a regular network cable (twisted pair). This allows you to combine PCs into one network to exchange data between them;
the router assigns a personal IP address from the DHCP server to each network device;
the Internet channel from the provider can connect to the router using the WAN interface;
Many routers are equipped with USB connectors.

Also, some routers may differ from their counterparts in the presence of various additional features:

The VoIP module allows you to use IP telephony services (there is a special connector on the case for connecting a telephone line);
The presence of a USB connector allows you to connect various devices directly to the router.

Typically, the more expensive the router model, the more capabilities it has. Many people do not know how to use various additional functions - all the necessary information is available in the accompanying documentation of the device. Every year, the manufacturer is increasingly simplifying the technology for setting up and using its devices, thereby making Wi-Fi Internet more and more accessible to the masses.

Most even not very experienced users have long known what the phrase Wi-Fi router means. Since the Internet and wireless communication technologies have already entered our lives very tightly. That is why most modern houses and apartments have a device that performs the function of distributing the Internet between individual devices.

Few people bother studying the capabilities of their Wi-Fi router. There is Internet, and that's fine. In fact, a good Wi-Fi router can do a lot of cool things. And to use all the features, you don’t need to have special knowledge, download alternative firmware and study hundreds of pages on forums. Let's show you how it worksusing the example of a router, which can be bought for 2,500–2,700 rubles.

1. Connect your network to your neighbor's Wi-Fi. Or anyone else

Let’s say a signal from a nearby cafe reaches you. Or a neighbor, out of the kindness of his heart, gave you the password for his Wi-Fi. Instead of connecting to the network from a smartphone, tablet or computer, connect to it through a router, and then use the free Internet from the router. This function is called "" (WISP), and it has several advantages:

Better signal. If on a smartphone a wireless network shows one or two bars and works somehow, then from a router the same network will give its full speed, and the connection will be much more stable.
Safely. You never know how security will fare on an unfamiliar Wi-Fi network. By connecting to someone else's Wi-Fi through a router, you are protected by the security measures built into it and do not expose your devices and their contents to someone else's network.
Backup Internet that connects automatically. If something suddenly breaks down with your main provider, the router will automatically switch to the backup channel, and you most likely won’t even notice it and will be able to continue using the Internet.
Backup Internet from a smartphone. Often, when there are problems with the Internet, we use our smartphone as an access point. The signal from it is weak and hits close. Create an access point on your smartphone, connect to your router as a “wireless provider”, and you will get a good, stable connection on all your devices.

2. Use multiple providers on one router

This feature is called Multi WAN. It allows you to connect as many providers as there are ports on your router, and additionally add a USB modem.

Let's say you have Internet access from two providers at once. One is the main one, the second is a reserve one with the cheapest tariff. This good practice, which allows you to stay online even if something happens to your main provider.

In order not to swap cables every time, not to reconfigure the router or computer, and not to do other time-consuming and energy-consuming things, just connect both cables to the router. The main port goes to the standard port (usually a different color), and the backup port goes to any other port. Configure the router once, and in the future everything will work and switch automatically.

3. Distribute the Internet from a USB modem through a router

This is possible if the router has a USB port, and you have a USB modem from a cellular operator, with which you can access the Internet from a laptop from anywhere.

Connect the modem to the router's USB port and perform a quick setup using. Now you have a backup Mobile Internet, which will turn on automatically if problems arise with the main provider.

This life hack will allow you to use a Wi-Fi network not only at the dacha, where there is no landline Internet, but also while traveling. You can find an adapter on the Internet to power the router from the cigarette lighter in your car. Connect a USB modem to the router, and all your passengers will be able to use the Internet while traveling - provided, of course, there is a cellular network signal.

If you have an external hard drive, connect it to the router via USB.

Activate the ability to download torrents in the router settings.

You can launch and manage downloads remotely through the My.Keenetic Android app.

Downloading and distributing torrents through a router occurs without the participation of a computer. By default, download and upload speeds are set so as not to clog the entire channel. You can change the speed in the settings. You won’t get more than 5 MB/s from the budget Keenetic Omni, but the Internet will not slow down when downloading.

The router can not only download, but also broadcast video to a TV via DLNA, and in the torrent settings you can select sequential torrent downloading to start watching a movie before the download is complete.

5. Access your router and home devices from anywhere

A free proprietary service, KeenDNS, is available to all “kineticists”, replacing any other DDNS services (such as No-IP and DynDNS) in a situation where you have a white but dynamic IP address.

What to do if the address is gray, as, for example, almost everyone has mobile operators for the connection described above via a USB modem or a backup one?

KeenDNS solves this problem:

It allows you to connect to the router even with a gray address using a convenient name like home.keenetic.link without the hassle of obtaining and registering an SSL certificate;
Provides access behind the gray address not only to the router, but also to the devices connected to it (for example, a heating boiler control system or the already mentioned torrent downloader) by a convenient name like device.home.keenetic.link.
Provides to home network over a pervasive SSTP tunnel that's easy to set up on Windows or an Android app.

6. Create Time Machine backups

Apple has stopped producing its routers, but the need to backup the MacBook has not gone away.

Enable backup Time Machine in the router settings by . You will again need an external hard drive - now it will also become a backup storage. Moreover, it is not at all necessary to format it into the apple file system HFS+, because the router can make backups on an NTFS disk.

If you need high backup speed, Keenetic Omni may not be able to handle it. Look towards the top-end routers Keenetic Giga or Ultra.

7. Control your flash drive from your smartphone without an OTG cable

This function will allow you to record or view files if you don’t have a computer at hand, and your smartphone does not support OTG, or the OTG cable has disappeared somewhere.

Connect the flash drive to the router and run it on your smartphone file manager like ES Explorer with support for network access. You will have full access to the contents of the flash drive, regardless of its file system.

8. Turn your router into a telephone exchange. Or something else

You can plug not only a modem or disk into the router’s USB port, but also a branded DECT set-top box. With it, your router will work as a wireless telephone exchange with support for up to 6 handsets. Everything necessary for this can be done without special knowledge.

Support for third party software packages () official firmware turns the router into a real Swiss army knife with a bunch of bells and whistles. You can install the rTorrent torrent client, an Asterisk IP-PBX telephone exchange, another DLNA server, and much more into the router. In routers Keenetic, the main firmware does not change, and you do not lose the warranty.

9. Save on VPN

Thanks to recent events on the Russian Internet, everyone now knows about VPN and its benefits.

Using a router, you can save a lot by purchasing just one license for one device from some good VPN provider, but use the service on all your devices at once.

To do this, just enable VPN not on one of the devices, but directly on the router. Now any smartphone, tablet or computer connected to the router will automatically access the Internet via VPN. If this does not suit you, go to your router settings and specify which gadgets should work through the VPN and which should not.

If you only want to use a VPN to improve your online security, you don't need overseas VPN servers, which means you don't need to pay for them. If you have a white IP, you can safely access the Internet through your own VPN while away from home. As a bonus, you'll have access to your home network and its content from anywhere in the world.

10. Make Wi-Fi faster and more stable

Most routers operate in the 2.4 GHz band. When several routers are located nearby - for example, in an apartment building - they interfere with each other. Imagine a bazaar: a bunch of people, everyone is shouting, nothing is clear. It’s the same with routers, only the quality and speed of the Internet drops.

The range is divided into several channels. For example, Vasya’s neighbor’s router works on channel 6, and Petya’s on channel 11. The router can monitor the current congestion of channels and even automatically switch to the least populated ones, but neighboring routers may also have the same function. What to do?

Create as many networks as your router allows. Give the networks different names so that your neighbors don’t figure out your cunning plan (and don’t forget to set passwords). All networks you create will be on the same channel. For any Wi-Fi analyzer, the channel will seem overloaded, and therefore it will consider it inappropriate to create a mesh in it. This means that the channel will remain entirely at your disposal.

Why can't my router do this?

Much depends on the developer of the router software. Some devices receive updates and all the newest features, while others remain on the old version. Users of the latter have to wriggle out and install custom firmware at their own risk, thereby losing the warranty on the device.

Keenetic uses a single operating system, which is constantly being improved and adds new features to all router models.

It doesn’t matter whether you use the top-end Keenetic Giga or the budget Keenetic Lite - you will always have the latest version of the operating system with all the new features.

Naturally, hardware limitations play a role. Cannot be used software update Grow a USB port for your router. A device designed only for 2.4 GHz will never learn to operate in the 5 GHz band. But if the device’s hardware meets the requirements for operation new feature, then you will receive it regardless of the model of your Keenetic.