Cat5e, Cat6, shielded or not, what length? Choosing the right network cable is not complicated once you know the key criteria. Here is a simple guide to properly wiring your business network.
Which cable category?
The category determines the supported speed and frequency:
- Cat5e: 1 Gbps, the minimum today.
- Cat6: 1 Gbps (up to 10 Gbps over short distances), the best default choice.
- Cat6a: 10 Gbps over 100 m, for high-performance networks.
- Cat7 / Cat8: specific uses and data centers.
The detailed table (speed, frequency, distance) is in our RJ45 wiring reference.
Shielded (STP) or unshielded (UTP)?
UTP (unshielded) is sufficient for most indoor installations. Prefer STP/FTP (shielded) near electrical sources, in industrial environments, or outdoors to reduce interference.
What length?
The golden rule of Ethernet: maximum 100 meters per copper link. Beyond that, the signal degrades; you need to switch to fiber optic and SFP modules.
Cable and PoE
PoE (power over cable) runs over copper: count on at least Cat5e, Cat6 to be safe. See our PoE budget calculator.
Straight or crossover cable?
To connect a device to a switch, use a straight cable. Crossover cables are now almost unnecessary thanks to auto-MDI/MDIX. Details in our RJ45 reference.
FAQ: network cable
Cat6 or Cat6a?
Cat6 is enough for Gigabit. Switch to Cat6a if you aim for 10 Gbps over 100 meters.
What is the maximum length?
100 meters over copper. Beyond that, switch to fiber.
Does the cable affect actual speed?
Yes: an insufficient category or too long cable limits speed. But the switch and network cards matter just as much.
For equipment, browse our network switches and SFP modules, and read our Ethernet switch guide.