Everything You Need to Know about Computer Communication Networks
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Connecting computers to a network is simple, once the hardware components are in place. This guide identifies the hardware that connects computers together in local networks, and local networks to the Internet. Several combinations of hardware that link computers are possible. Connecting systems allows users to share media, files, participate in gaming, and other activities. Computer networking hardware also facilitates access to the Internet, and the wide resources it offers.
What Is a Computer Network?
Computer networks link two or more computers or computer-driven devices together electronically. The electronic link is performed with cables, or a combination of cables and wireless links. Networked computer systems and devices are capable of sharing data, files, interactive chatting, video conferencing, gaming, and/or connections to resources on the Internet.
The Internet is reached through a connection to a single computer or a local network of computers.
The most basic computer network is a local area network (LAN). The simplest LAN consists of two computers that communicate with each other. Other resources commonly found on LANs are printers, scanners, gaming hardware, mobile devices, and networked video cameras.
Typical LAN resources can be shared with other computers. For instance, you can print from a printer configured as a shared network resource, or watch the video feed from a doorbell camera.
What Hardware Is Needed to Connect to a Network?
Each member of a computer network has a minimum of three computer hardware components. These components are:
- A network interface
- A communications medium
- At least one other computer (or computing device) which also possesses #1 and #2.
A computer needs a network interface as an entry and exit point for network communications. Typically, there are two types of network interfaces: wired and wireless. The wired interface is usually a connector located on the side or rear of the computer, having two tiny LEDs. A wireless interface is either hidden or has exposed antennas, and uses invisible radio signals to connect to another computer or device.
There are other network interfaces available. For instance, the Bluetooth protocol, which like other wireless interfaces, uses invisible radio waves. Other devices may support networking over USB cabling, although this is uncommon and typically slower than other methods.
Wired Network Hardware - What Do You Need?
Wired networks typically use a cabling system called Ethernet. Ethernet cables can be up to 100 meters long, and have “RJ-45” connectors at each end.
A single Ethernet cable is the bare minimum hardware needed for two computers to connect to each other. One end is plugged into the first computer, and the other end is plugged into the second computer. Adding a third computer, however, requires an additional network hardware device, called a router.
When connected together, this minimal network illuminates the LED lights on either side of the jack located on the computing devices. If there are no lights, the cable may be broken, wired incorrectly, or simply incompatible with one of the devices. In this example situation, a “crossover” cable must be used.
Computer Hardware Needed to Network Three or More Devices
A router is needed when three or more computers/devices need to be connected. A router connects and coordinates communications among members of a network.
Modern routers typically have switching functions that confine the data shared between the two computers/devices that are communicating. Modern routers usually have both wired and wireless networking capabilities.
Another option may be a wide area network (WAN) interface. This interface is used to connect to a device serving a connection to the Internet. The router’s switching function is usually transparent in operation to the communicating computers. Data is switched to the correct destination while devices are communicating.
A router can also include other functions and sometimes be referred to by other names, including “Ethernet switch”, or “gateway”.
The wired Ethernet network interface connects through a cable to another computer. However, two computers having a wireless network interface can connect to each other directly without a cable.
A wired network needs sufficient cabling if more than two computers or devices are to be connected. Subsequent devices are usually connected to an Ethernet hub or switch that coordinates network communications signals and data. A hub or switch device only connects devices that are connected locally, over a LAN. A computer network router or gateway, however, is used to connect LANs to other networks, including the Internet. In many computer networks, these functions are combined transparently in the same device and the terms switch, hub, router, and gateway describe the same device.
Each router in a wired network has jacks with two small LEDs. The LEDs activate to indicate a correct wiring between it and the computer/device it’s connected to by cable. If only one LED lights, the speed of the connection is 100 megabits per second on the indicated jack. If both LEDs light, there is a gigabit per second connection on the indicated jack.
Most consumer and small business routers also contain the radios needed to connect computers/devices wirelessly. This scheme, called “WiFi”, usually comes in two types, 2.4 GHz and 5 GHz. Both radio types are often seamlessly offered in routers supporting wireless connectivity. The difference between the radios are that the 2.4GHz radios are slower and more crowded, especially in urban areas. Whereas 5Ghz radios are faster and often have more room.
Devices called wireless hotspots provide connectivity to the Internet. The hotspot routes wireless traffic to a mobile device or dedicated cellular hotspot. Some hotspots contain jacks for wired connections that follow the same cabling requirements needed for routers.
Computer Hardware Needed for Wired Versus Wireless Networks
Wired networks need cabling, which is limited to 100 meters maximum per cable length. Additional distance between networked devices requires the use of a switch or hub. A single switch or hub can connect two or more devices. Each device can be 100 meters from the switch, for a total 200 meter distance until another switch is needed.
The disadvantages to cabling is that cables must be protected from weather, physical strains, disconnections, slicing, and cuts. They must also be kept distant from power cables or sources of radio or other electrical interference.
Network cabling through walls, ceilings, and other barriers is often regulated, and may require professional installation in some instances.
When wireless computer networking hardware is used, communication speed among computers/devices in the network slows as the distance between each networked device increases. Signal barriers between the wireless computer devices and their wireless connectivity devices, such as a wireless router, can also interfere. Although wireless signals bounce and can penetrate walls, some objects strongly block the wireless network signals, thereby cutting speed.
In urban areas, many wireless computer hardware users in adjacent locations compete for the available radio space allocated for wireless networking signals. They can interfere with each other in unpredictable ways, and may slow overall computer hardware networking speeds.
By contrast, wired computers have the same effective speed no matter the cable length. They are also not limited in speed when in close physical proximity to other cables, or wireless hardware components in the network.
Wireless networks benefit from wireless networking range extenders, or range-extending wireless mesh networking components. Wireless networking extenders and wireless meshes add additional hardware that is deployed to extend the distance range while retaining speed. They also overcome signal-blocking obstacles such as walls, metal barriers, and floors. Wireless hardware network extenders and meshes are often sold by the same vendors as routers.
Connecting LANs to the Internet
A LAN can be connected to the Internet through fiber optic cable, coaxial cable, satellite connection, cellular gateway, or a mobile device gateway/router. An Internet Service Provider (ISP), may offer customers a device, sometimes called Customer Premises Equipment (CPE) that contains wired and/or wireless LAN connections.
The CPE device is usually a network modem, cable modem, satellite router, or wireless modem. This network hardware arbitrates and routes LAN traffic, as well as traffic destined to communicate to the Internet. The ISP may or may not have CPE settings that can be customized by the consumer.
There may be only one wired jack on the CPE device. Consumer routers connect the WAN interface of their router to the single wired jack of a CPE device where present. If the CPE device has more than one jack, then wired computers, or another router, switch, or gateway can be added to these additional jacks.
The CPE hardware may or may not include wireless computer/device connectivity. Where not included, a wireless hub/router/mesh/bridge must be connected to the CPE in order to provide wireless signals for a LAN.
Computer Network Settings
Each computer hardware CPE, router, or other wired/wireless device has a settings page that can be accessed from a Web browser. Instructions on what is needed are contained in the instructions that come with the device.
Many computers are automatically connected to a CPE, router, modem, or other wired/wireless device through a wireless connection. Securing the device simply involves setting a password. Often, it is the only setting necessary for many computer networking hardware installations.
Computer operating systems search for networking hubs, routers, gateways, and switches using the Dynamic Host Configuration Protocol (DHCP). When the computer/device is correctly connected (either wired or wirelessly), DCHP provides technical connection information that allows it to connect to the LAN.
The device serving as a LAN controller starts with a pool allocated to distribute technical information, called the DHCP address pool. Some consumer and small business router/hubs/CPE run out of addresses allocated in the pool, which must be unique. A pool can be increased through settings available on the router/hub/gateway/CPE settings page. If network connectivity is managed by outside resources, settings are controlled by accessing an “external administrative control” page pertinent to that specific installation.
Troubleshooting a Consumer Network
Home and small business networks are designed to start in a certain sequence. When power to the devices becomes interrupted, it’s best to restart all networked devices. Turning off devices, then restoring power to them can restore network operation.
To perform this, turn off, or power down all devices, including the CPE, routers, and computers. Restore power first to the CPE device(s), and wait for two minutes. Next restore power to the router (or hotspot, gateway, etc.), pause two minutes, then restore power to computers/devices. These actions often restore computer hardware networking functionality.
A simple network connection takes place between two computers using their network interfaces, either wired or wireless. Networking more than two computers/devices requires a router.
Routers may be standalone, or have built-in Internet connectivity to for wired and/or wireless computers/devices. Wired and wireless LAN connectivity can be extended to allow expansion of the physical area using extra routers, wireless network extenders, or mesh network components.
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