Can anyone rate CAT classes

CAT 5, CAT 6, CAT 7 & CAT 8 - What are the differences?

Ethernet cables are divided into so-called CAT classes. In German they also have the designation KAT, for category. What are the differences and which cable is the right one for which application?

CAT 5: The most common cable *

Inexpensive and usually sufficient - Category 5 is the most widespread standard among network cables.

  • CAT-5 cables are usually completely sufficient for use at home.
  • They reach their limits at transmission rates above 1 Gbps;
  • However, hardware such as computers and hard drives are usually the bottleneck in the system.
  • They are still installed today in the professional sector, but much less often than other standards.

* What hardly anyone knows: Contrary to popular misconceptions, the term “cable” is not quite correct here - experts know how to differentiate between cables and wires. We explain the difference in a blog post.

  1. Outer jacket: Pressure-extruded, flame-retardant TPE mixture
  2. Overall screen: Extremely bending-resistant braid made of tinned copper wires
  3. Screen foil: Aluminum-clad plastic film
  4. Inner jacket: Pressure-extruded, gusset-filling TPE mixture
  5. Banding: Synthetic fleece
  6. Core insulation: Mechanically high-quality TPE mixture, according to the bus specification
  7. ladder: Fine-wire strand in a particularly bending-resistant version made of bare copper wires
  8. Strain relief: Tensile core element

CAT 6: Ideally suited for companies

CAT 6 cables are mainly found in the professional sector

  • Category 6 cables can only reliably transmit signals up to 50 m in length.
  • The range can be multiplied with interconnected switches.
  • The CAT-6a standard is even suitable for 10 Gigabit Ethernet thanks to individually shielded wire pairs.

CAT 7: For the most demanding applications

CAT-7 cables allow even higher transmission rates and are even better shielded.

  • All cables of category 7 have four separately shielded wire pairs, which in turn share a shield. This means that they are optimally protected against external interference.
  • Two standardized connector types for CAT 7 network cables.
  • They are recommended for future security of the infrastructure in new buildings.

CAT 8: Extreme speed for data centers

Category 8 cables were developed exclusively for data centers, because here cables between routers and servers are usually short. They enable extremely fast data transfers without the use of fiber optic cables.

They enable extremely fast data transfers without the use of fiber optic cables.

  • Category 8 supports by far the highest operating frequencies.
  • The standard only supports transmission over very short distances.
  • Unbelievable transfer rates of up to 40 Gbps are possible.
  • These lines are well shielded against interference signals.
  • They are available in so-called 8.1 and 8.2 versions:
    • 8.1 uses standard RJ45 plugs.
    • 8.2 uses special connectors, although the specification is still under development.


CAT 5 and CAT 6 cables are ideally suited for most applications. If you want to build a future-proof house or need data transmission rates over 1Gbps, CAT 7 cables are the best choice, especially since these are becoming cheaper and better protected against interference signals.

Did you knowthat you can also transmit electricity via Ethernet cables? Find out more about this in our article on PoE.

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