When it comes to creating a stable wired connection between a router and a personal computer, users often encounter confusion over terminology. Many names are used: network cord, internet cable, LAN cable, or simply "Wi-Fi cable." However, to correctly select equipment and configure a network, it is necessary to know the exact technical name and characteristics of this infrastructure element.
The main name used by computer network engineers and specialists is twisted pairThis name reflects the cable's internal structure, where insulated copper conductors are twisted together in pairs to protect against electromagnetic interference. In retail, a ready-to-use section of such cable with pre-installed connectors is most often called patch cord (from the English "patch cord"). This term is the most accurate answer to the question of what the wire that connects devices in a local network is called.
Understanding the difference between the cable type and the name of the finished product is critical when purchasing. If you need to run a cable inside a wall, you buy a coil of twisted pair cable and crimp it with connectors. However, if you simply need to connect a router on a desk to a laptop, you buy a pre-made patch cord of the required length. Choosing the wrong cable type can lead to unstable network performance or failure to achieve the provider's stated speeds.
⚠️ Caution: Don't confuse a network cable with a telephone cable. The connectors may appear similar, but a telephone cable (RJ-11) is narrower and has fewer contacts. Trying to insert it into the network card may damage the port.
Main types and categories of network cables
Choosing the right cable directly impacts the maximum data transfer speed in your local network. The de facto modern standard is Category 1 cable. Cat 5e (Category 5 enhanced). It can deliver speeds of up to 1 Gbps over distances of up to 100 meters, fully covering the needs of most home and office ISP plans. This cable typically contains eight wires, organized into four pairs.
For more demanding users using equipment with speeds of 2.5, 5 or 10 Gbps, category cables are relevant Cat 6 And Cat 6aThey are tightly twisted and often feature a central plastic separator, which minimizes crosstalk between pairs of wires. The use of such cables is becoming standard in new home and office networks, providing years of performance reserves.
There are also shielded versions of cables, the marking of which includes the letter F (Foil) or S (Shield). For example, FTP or S/FTPThese cables have an additional layer of foil or metal braiding along their entire length. This is necessary in environments with strong electromagnetic interference, such as when laying cables near power lines or in industrial facilities.
When choosing a cable for home use, it's important to pay attention not only to the category but also to the core material. For fixed indoor installations, a cable with cores made of monolithic copper (Solid). If the cable will be frequently moved, bent, or used to connect laptops, it's better to choose a stranded cable, which is more flexible and kink-resistant.
Cable construction: what does it consist of?
The internal design of a network cable is an engineering compromise between cost, flexibility, and interference protection. The core of the design is copper conductors, each covered with colored insulation. The colors are not random and comply with international color coding standards, allowing for proper crimping of connectors.
The wires are twisted in pairs with different twist pitches. This technology gives rise to the name "twisted pair." The different twist pitches of each pair are necessary to minimize the influence of one pair on the other (crosstalk). Without this simple yet effective measure, data transmission at high frequencies would be impossible due to the enormous number of errors.
The twisted pairs may be surrounded by an additional aluminum foil shield, topped by an outer jacket of PVC or polyethylene. For outdoor installations, a cable with a black polyethylene jacket is used, which is resistant to UV radiation and temperature fluctuations, unlike the gray or white office cable.
What's inside a thick Cat 6 cable?
A plastic cross-shaped spacer is often found inside Category 6 cables. This keeps the wire pairs apart, preventing them from touching and reducing interference, which is critical for high frequencies.
Copper quality also plays a role. Cheap cables may be made of copper-clad aluminum (CCA) rather than pure copper. These cables have high resistance, conduct signals poorly, and are extremely brittle when bent. For a reliable connection between your computer and router, always choose cables made of oxygen-free copper (OFC).
Connectors and connection standards
At the ends of a network cable, connectors are installed, which in everyday life are often called "plugs." Technically, this connector is called RJ-45 (Registered Jack 45). It has 8 contacts and a plastic retainer (called a "tongue") that prevents the cable from accidentally falling out of the port.
There are two main pinout standards (the order of the colored wires inside the connector): T568A And T568BIn the modern world, the standard is used almost everywhere. T568BThe main rule of installation is that both ends of the cable must be terminated using the same standard. If one end is terminated using pattern A and the other using pattern B, the result is a so-called "crossover," which is rarely used these days, as modern network cards can automatically detect the cable type.
The process of installing a connector is called crimping and is performed using a special tool called a crimper. During crimping, the connector's blades cut through the wire insulation and penetrate the copper core, establishing electrical contact. Crimp quality directly impacts connection stability: poor contact leads to packet loss and reduced speed.
How to properly connect a computer to a router
Physically connecting a wired internet connection is a simple procedure, but it requires attention to detail. On the back of the router, there are usually several ports, colored yellow and labeled as LAN (Local Area Network). The port through which the Internet comes from the provider is usually blue and labeled WAN or Internet.
To connect a computer, you need to insert one end of the patch cord into any free port. LAN on the router, and the other end into the computer's network card. The connectors are shaped to prevent them from being inserted incorrectly, but you must apply firm force until you hear a distinctive click.
☑️ Connection check
Once physically connected, the operating system should automatically detect the network. A monitor or globe icon without the yellow exclamation mark will appear in the taskbar (tray). If the router is configured correctly and is distributing IP addresses (DHCP is enabled), the internet will be up and running immediately.
In some cases, especially on desktop PCs, you may need to install network card drivers if the system doesn't recognize the device. Windows 10 and 11 typically find drivers automatically, but specific gaming cards or older models may require manual installation from a disc or the motherboard manufacturer's website.
Comparison of characteristics of different cables
When choosing a cable, it's important to consider not only its category but also other parameters, such as jacket type, shielding, and conductor material. Below is a table that helps compare the key characteristics of popular network cable types for different use cases.
| Characteristic | Cat 5e (U/UTP) | Cat 6 (U/UTP) | Cat 6a (F/UTP) | Cat 7 (S/FTP) |
|---|---|---|---|---|
| Max. speed | 1 Gbps | 10 Gbps (up to 55 m) | 10 Gbps (up to 100 m) | 10 Gbps+ |
| Frequency | up to 100 MHz | up to 250 MHz | up to 500 MHz | up to 600 MHz |
| Screen | No | No (there is often a separator) | Foil (general) | Braid + Foil |
| Application | Home, office (standard) | Home, office (future) | Server rooms, data centers | Special tasks |
The table shows that for most home applications, purchasing Cat 7 or even Cat 6a cables is overkill unless you have the appropriate active equipment. However, if you're running cable inside the walls of a major renovation, Cat 6 makes sense, as the price difference is minimal and the safety margin is higher.
It's also worth noting the difference in cable diameter. Higher-category cables (Cat 6 and above) are typically thicker and stiffer due to the dividing wall and denser insulation. This can make it difficult to install them in narrow raceways or baseboards, so the physical dimensions of the conductor must be taken into account when planning the route.
⚠️ Caution: When installing cable inside walls, avoid sharp bends. The bending radius of twisted pair cables should not be less than 5-8 times the cable's outer diameter. Violating this rule will result in deformation of the conductors and signal loss.
Cable length and signal loss
One of the frequently asked questions concerns the maximum cable length that guarantees stable network operation. According to the standard IEEE 802.3, the maximum length of a twisted pair segment is 100 metersWithin this distance, the signal attenuates slightly, and transmission errors do not occur, provided the installation is of high quality.
For home use, cable lengths typically range from 1 to 20 meters. It's important to understand that buying an extra 50 meters of cable to connect two rooms isn't a good idea. Excess cable, tightly coiled, creates inductance, which can degrade signal quality, especially at high speeds. It's best to measure the exact distance and purchase or make a patch cord of the appropriate length.
If the distance between the router and the computer exceeds 100 meters, using a standard twisted pair cable is impossible without additional active equipment. In such cases, fiber optics are used or intermediate switches are installed to regenerate the signal.
It's also worth considering that very short cables (less than 30 cm) may not work reliably with some network cards due to impedance issues, although modern standards try to minimize this problem. Standard patch cord lengths in stores are: 1 m, 2 m, 3 m, 5 m, and 10 m.
Common problems and their solutions
Even with high-quality equipment, users may encounter connection issues. The most common is an unresponsive network card. If the indicators on the router and computer ports don't light after connecting the cable, first check the integrity of the cable itself and the tightness of the connectors.
Another common issue is limited access or a "No Internet Access" status, even though there is a physical connection. This often indicates an IP address conflict or incorrect router settings, rather than a wiring issue. However, if the connection speed automatically drops to 10 Mbps instead of 100 or 1000 Mbps, this is a sure sign of a poor connection in one of the wires or a damaged cable.
A LAN tester is a convenient tool for diagnosing cable integrity. It consists of two parts: a base unit and a remote module. When the cable is connected, the tester checks each of the eight wires in turn. If one of the lights is out of order or does not light up, the cable is damaged or improperly terminated.
Why are only 4 lights on the tester?
For a speed of 100 Mbps, four working wires are sufficient. If the cable is damaged or improperly terminated, and only four of the eight wires are working, the connection will be established, but the speed will be limited to 100 Mbps.
If a cable is damaged (pinched by furniture, bitten by animals), it doesn't have to be thrown away. You can use RJ-45 splices (RJ-45-to-RJ-45) or install a new connector if you have extra length. However, any splice (or twisted connection) introduces additional loss, so a solid cable is always preferable.
Details that are often forgotten
When setting up a wired network, it's important to keep fire safety in mind. Cables installed in office buildings and public spaces must be labeled. LSZH (Low Smoke Zero Halogen). This type of fire retardant fire retardant emits no acrid smoke or halogens during combustion, which is critical for evacuating people. While this is less relevant for homes, using non-flammable materials is always a good idea.
PoE (Power over Ethernet) is also worth mentioning. This technology allows for the transmission of electrical power along with data over the same cable. It is used to power IP cameras, access points, and VoIP phones. If you plan to connect such devices, make sure your cable and connectors can handle the additional current, although this is usually not an issue for standard Cat 5e cables.
The cable's outer sheath can be made of various materials. For offices, PVC is the standard. For outdoor use, polyethylene (PE) is recommended, as it is resistant to sun and frost. There are also cables with an internal cable for suspension between buildings. Using this type of cable outdoors will result in its rapid deterioration under ultraviolet radiation.
Can you use a telephone cable instead of a network cable?
No, you can't. Telephone cable (smaller-diameter twisted pair, usually 2 or 4 conductors, RJ-11 connector) is not designed to transmit high-frequency Ethernet data. Even if you physically manage to insert the connector (which is difficult), the network will not work, or the speed will be extremely slow and unstable. Furthermore, you can damage the contacts on the network card.
Does cable color affect signal quality?
The color of the outer jacket (blue, white, black, red) is purely a matter of aesthetics and marking. The insulation color has no effect on electrical performance or data transmission quality. Choose a color that best complements your decor or helps separate network zones.
Is shielding (FTP) necessary for a home router?
In most cases, shielding is not required for apartments or private homes. UTP (unshielded) cables are excellent at preventing interference within residential spaces. Shielding is only necessary if the cable runs close to powerful electrical appliances or along power lines over long distances. Furthermore, shielded cables require grounding of the shield, otherwise they act as an antenna, picking up interference.
What to do if the connector is broken?
The plastic retainer or the plastic connector housing itself cannot be repaired. You will need to purchase new RJ-45 connectors (they're inexpensive) and a crimping tool. The old connector is cut off, the new section of cable is stripped, and the crimping is done again. If you don't have a crimping tool, you can use a longer, ready-made patch cord or call a technician.
Is it true that coiled cables perform worse?
Yes, it's true. Tightly coiling excess cable creates an inductive coil, which can distort high-frequency signals, especially in high-grade cables. If the cable is longer than necessary, it's best to buy a shorter one or carefully tuck the excess cable away from any kinks or kinks.