Ethernet - Which cables to choose? Categories and applications

Ethernet is one of the most widely used standards in computer networks, used in both office and home settings. Choosing the right Ethernet cable is crucial to ensure reliability and high data transmission speeds. In this article, we will look at the different categories of Ethernet cables and patchcords, discuss their use, advantages and disadvantages, and suggest which cable to choose depending on your needs.

A patchcord is a short cable that is most often used toconnect devices in a local area network (LAN) within short distances, such as between a computer and a router or switch. As a rule, patchcords are terminated with standard RJ45 plugs, although they can also come with other terminations depending on requirements.
Patchcords are available in different categories(Cat 5e, Cat 6, Cat 6a, Cat 7, Cat 8), which affects their speed and resistance to interference. They are shorter cables, so their purpose is to provide a stable connection with minimal signal loss. It is worth paying attention to the selection of the right patchcord for optimal network performance.

Ethernet cables differ in the categories that determine their technical parameters. Here are the most popular ones:
Cat 5e - The basic standard designed for gigabit networks, offering speeds of up to 1 Gbit/s at 100 MHz. It is suitable for home networks and small offices, but may be insufficient for future expansions.
Cat 6 - An improved version that supports speeds of up to 10 Gbit/s at 250 MHz over distances of up to 55 meters. Compared to Cat 5e, it provides better interference protection and more stable operation at higher speeds.
Cat 6a - An upgraded cable that supports 10 Gbit/s over a full length of 100 meters and a frequency of 500 MHz. It features low interference and is ideal for high-performance networks in offices and large apartments.
Cat 7 - Operates at 600 MHz, supporting 10 Gbit/s, but with mandatory shielding. However, this standard is not approved by TIA/EIA, which limits its popularity. Instead of RJ45 connectors, GG45 or TERA connectors are used.
Cat 8 - Designed for speeds of 25-40 Gbit/s, but over short distances (up to 30 meters). It operates at 2000 MHz and is mainly used in data centers and server rooms.

Category	Maximum speed	Frequency	Length 1 Gbit/s	Length 10 Gbit/s	Shielding
Cat 5e	1 Gbit/s	100 MHz	100 m	None	Optional (UTP/STP)
Cat 6	1 Gbit/s, 10 Gbit/s (up to 55 m)	250 MHz	100 m	55 m	Optional (UTP/STP)
Cat 6a	10 Gbit/s	500 MHz	100 m	100 m	Optional (UTP/STP)
Cat 7	10 Gbit/s	600 MHz	100 m	100 m	Mandatory (S/FTP)
Cat 8	25-40 Gbit/s	2000 MHz	30 m	30 m	Mandatory (S/FTP)

Cat 7 cable offers better protection against interference due to shielding, but in most cases this does not bring noticeable benefits in practice. Cat 6a cable is less expensive, supports 10 Gbit/s and is officially certified. In situations with minimal interference, Cat 6a performs just as well, and its cost is significantly lower.

Shielding in Ethernet cables (STP, FTP, S/FTP) is useful when the cable is exposed to high electromagnetic interference. Shielding should be used when:

• Cables carried out near sources of interference (e.g., devices that emit strong electromagnetic fields).
• Installations along power lines.
• Networks in industrial environments or data centers.

In other cases, unshielded Cat 6a or even Cat 5e cables will be perfectly adequate.

Why isn't Cat 8 needed in home environments?
Despite its impressive performance, Cat 8 has its limitations:

• The maximum length is only 30 meters, making it unsuitable for long connections.
• High price: It costs significantly more than Cat 6a.
• Being obsolete in home networks: 10 Gbit/s can be achieved with cheaper cables.

Cat 8 is mainly designed for server rooms and data centers. For homes and offices, it is too advanced.

The choice of Ethernet cable depends on your specific needs:

• For everyday Internet, Cat 5e or Cat 6 will suffice.
• For 10 Gbit/s networks, Cat 6a is the best choice - it offers good value for money.
• Cat 7 does not offer an advantage over Cat 6a.
• Cat 8 is designed for server rooms and is not applicable to home networks.

If you plan to expand your network in the future, Cat 6a will be the best choice.

Author:
Aliaksandr Roslikau