Structured cabling in datacenters
Copper cabling (UTP/STP)
Twisted-pair copper with RJ-45 connectors is the workhorse for connections inside the rack and between nearby racks. Pick the category based on the speed you need and the distance you have to cover.
| Category | Max speed | Bandwidth | Max distance | Typical use |
|---|---|---|---|---|
| Cat5e | 1 Gbps | 100 MHz | 100 m | Legacy networks, offices |
| Cat6 | 10 Gbps | 250 MHz | 55 m (10G) / 100 m (1G) | Current general standard |
| Cat6a | 10 Gbps | 500 MHz | 100 m | Recommended for datacenter |
| Cat7 | 10 Gbps | 600 MHz | 100 m | Fully shielded; uses GG45/TERA connectors, not standard RJ-45, so it is rare in practice |
| Cat8 | 25/40 Gbps | 2000 MHz | 30 m | Short switch-to-switch links |
Datacenter recommendation: Cat6a as a baseline. It carries 10 Gbps over the full 100 meters and has much better crosstalk protection than Cat6.
Fiber optic cabling
Fiber carries data as light pulses. It reaches far longer distances than copper and is immune to electrical interference.
Single-mode vs multimode
| Property | Multimode (MMF) | Single-mode (SMF) |
|---|---|---|
| Core diameter | 50 or 62.5 µm | 9 µm |
| Distance | Up to 400 m at 10G (OM4) | 10 km standard, 80 km+ with long-reach optics |
| Transceiver cost | Lower | Higher |
| Jacket color | Orange (OM1/OM2), aqua (OM3/OM4), lime green (OM5) | Yellow |
| Use | Inside the datacenter | Between buildings, campus, WAN |
OM grades (multimode)
| Grade | Speed/distance | Notes |
|---|---|---|
| OM3 | 10G up to 300 m | Minimum you should buy today |
| OM4 | 10G up to 400 m, 100G up to 150 m | Standard in new builds |
| OM5 | Adds SWDM support at 150 m | For wavelength multiplexing; niche |
Common connectors
- LC: small form factor, the most common in datacenters.
- SC: larger, push-pull, still found on older patch panels and ISP gear.
- MPO/MTP: multi-fiber connector used for 40G/100G parallel links.
Transceivers, DAC and AOC
Transceivers are pluggable modules that convert electrical signals to optical (and back). They go into switch or server ports: SFP (1G), SFP+ (10G), SFP28 (25G), QSFP+ (40G), QSFP28 (100G).
DAC vs AOC: for short runs (under ~5 m), DAC cables (Direct Attach Copper) are cheaper than two transceivers plus fiber. AOC cables (Active Optical) cover up to ~30 m with the optics built into the cable ends.
Patch panels
A patch panel is a panel of numbered ports that terminates the permanent cabling. Fixed runs go from the panel to wall outlets or equipment; short patch cords connect the panel to the switch.
Server → permanent run → [Patch panel] ← patch cord → [Switch]This means moves and changes only touch the patch cord. You never re-pull the permanent cable, and switch ports wear out less.
Cabling best practices
- Label everything: both cable ends, patch panel ports and switch ports.
- Keep copper and fiber apart: dedicated cable managers for each type.
- Right lengths: no taut cables, no coiled excess blocking airflow.
- Respect bend radius: at least 4x cable diameter for copper, 10x for fiber.
- Color-code: distinct colors for management, data, storage and uplinks.
- Document every connection: source, destination, cable type, VLAN.
Cabling in CreaRack
CreaRack turns that documentation rule into a workflow. [[crearack—racks—port-mapping]] lets you read live port and VLAN configuration from your switches and document which port connects to which device. From there, [[crearack—network—cable-report]] generates a self-contained report with per-rack connection tables, a cable inventory and a topology diagram — ready to print or hand to a colleague.
Related
- [[crearack—racks—port-mapping]] — document ports, VLANs and cabling per device
- [[crearack—network—cable-report]] — export the full cable documentation
- [[crearack—redes-infra—switches-routers]] — the equipment the cabling connects
- [[crearack—redes-infra—alimentacion]] — rack power distribution
- [[crearack—redes-infra—refrigeracion]] — cabling affects airflow too
- [[crearack—redes-infra—vlans]] — logical segmentation on top of the cabling
Véase también
- [[crearack—redes-infra—switches-routers]]
- [[crearack—redes-infra—alimentacion]]
- [[crearack—redes-infra—refrigeracion]]
- [[crearack—redes-infra—vlans]]
- [[crearack—racks—port-mapping]]
- [[crearack—network—cable-report]]