Network cabling: Cat6 or fiber optic?
Network cabling stays in place for years and replacing it is expensive, so getting the choice right at the start matters. Most enterprise networks combine copper cable and fiber optics, and each has its place.
Copper cable (Cat6 and Cat6A)
Under structured cabling standards, each copper channel is limited to 100 meters: about 90 meters of permanent cable in the wall or duct plus 10 meters of patch cords at both ends.
- Cat6 is the most common choice for gigabit networks and for powering cameras and access points with PoE; it supports 10 gigabits only over short distances (about 55 meters).
- Cat6A supports 10 gigabits over the full 100 meters and is better suited to server rooms and runs that will need higher speeds.
Fiber optics
Fiber carries data as light, so it has no copper distance limit, is immune to electromagnetic interference and creates no electrical path between two buildings. That last point is very important for protection against lightning damage and earth-potential differences between buildings.
- Multimode fiber (such as OM3 and OM4) suits distances inside a building or campus; for example, it carries 10 gigabits up to about 300 meters on OM3 and about 400 meters on OM4.
- Single-mode fiber is used for long distances, from several hundred meters to tens of kilometers, and for city networks.
Which to use where?
- From the floor rack to the user's desk, camera or access point: Cat6 or Cat6A copper
- Between floors and the main server room (backbone): fiber optics, or Cat6A over short distances
- Between buildings and masts: fiber optics, or a radio link when cabling is not possible
Installation quality matters as much as cable type
Respecting the bend radius, keeping distance from power cables, labeling both ends of every cable and testing each link with a certification tester after installation make the difference between a stable network and one full of outages. After installation, ask for the as-built plan and the test report for every point.