Copper Cabling: Cat5e, Cat6, and Cat6A

The Standards

Cat5e (Enhanced Category 5):

• Maximum speed: 1 Gbps at 100m
• Frequency: 100 MHz
• Status: Adequate for 1G. Still functional in millions of installations. Not recommended for new work.

Cat6 (Category 6):

• Maximum speed: 1 Gbps at 100m; 10 Gbps at up to 55m
• Frequency: 250 MHz
• Status: The current baseline for most new office installations. Supports 10G for shorter runs, better noise rejection than Cat5e.

Cat6A (Augmented Category 6):

• Maximum speed: 10 Gbps at 100m (10GBASE-T)
• Frequency: 500 MHz
• Status: The right specification for new installations where 10G to the desktop is a current or foreseeable requirement. Larger diameter, more stringent construction, more expensive, harder to work with.

What This Means for New Installations

For new office buildouts: Cat6A. The incremental material cost over Cat6 is modest relative to total installation cost (materials are typically 30–40% of total; labor is the larger component). Cat6A gives you 10G-ready infrastructure through multiple switch and workstation refresh cycles.

Cat6 is acceptable for budget-constrained projects where 10G to the desktop is genuinely not anticipated.

Cat5e should not be specified for new work. If you're inheriting Cat5e infrastructure, it's adequate for 1G applications until there's a reason to replace it. Don't extend it.

PoE and Heat

Higher PoE standards (IEEE 802.3bt / PoE++) deliver up to 90W per port. That power runs through the cable as current, generating heat. Dense PoE deployments — a ceiling full of access points, a conference room with multiple powered devices — can raise cable temperatures meaningfully in a bundled conduit.

Cat6A handles PoE thermal load better than Cat6 due to its construction. In any high-density PoE environment (12+ PoE devices per 100-cable bundle), Cat6A is the appropriate specification even if 10G bandwidth isn't the primary driver.

The Long View

Structured cabling outlasts everything else in your infrastructure. A properly installed Cat6A plant should serve through 3–4 switch generations and 5–6 workstation refresh cycles before the cabling itself becomes the limiting factor.

The labor cost to re-cable an office — pulling cables, coring walls, terminating jacks — is typically 2–5x the material cost. Specify the category you want to live with for 15 years.