Frequently Asked Question
Structured Cabling 2025
Copper vs. Fibre – Which Cable Is Right for Your Network?
Below is a concise, practical guide to help you decide between copper Ethernet (Cat5e / Cat6a / Cat8) and fibre‑optic (multimode OM4/OM5 or single‑mode OS2) for any new drop, inter‑building link or data‑centre connection.
1. Short‑run desktop drops (≤ 100 m)
| Cable | Max speed (typical) | Distance for that speed | Typical use‑case | Pros | Cons |
|---|---|---|---|---|---|
| Cat5e | 1 Gbps (guaranteed) – 2.5 Gbps (often) – up to 5 Gbps on very short, high‑quality runs | 100 m @ 1 Gbps, ~50‑100 m @ 2.5 Gbps, | Standard office desks, conference‑room PCs, printers | • Cheapest of the lot • Easy to terminate • Compatible with all existing RJ‑45 hardware | • No guaranteed 10 Gbps • Limited future‑proofing |
| Cat6a | 10 Gbps (guaranteed) | 100 m | Workstations that may need 10 Gbps now or later, high‑density PoE+ | • Supports 10 Gbps for the full 100 m • Better crosstalk performance than Cat5e • Still uses RJ‑45 | • Thicker, less flexible • More expensive to terminate and test |
| Cat8 | 25 Gbps / 40 Gbps | 30 m max | Data‑centre top‑of‑rack, high‑performance compute clusters | • Highest copper speeds currently defined • Shielded (S/FTP) reduces EMI | • Very stiff, hard to pull through conduit • Costly; limited to short runs • Requires Cat8‑rated connectors and certification |
Recommendation for most UK offices
- Cat6a is the sweet spot: it future‑proofs you to 10 Gbps without the handling headaches of Cat8.
- Use Cat5e for economy and ease of installation.
2. Inter‑building or campus links (50 m – 400 m)
| Fibre type | Bandwidth (typical) | Reach @ that bandwidth | Typical use‑case | Pros | Cons |
|---|---|---|---|---|---|
| OM4 multimode | 40 Gbps / 100 Gbps (using 850 nm VCSELs) | 150 m @ 40 Gbps, up to 300 m @ 100 Gbps (often 400 m with newer transceivers) | Building‑to‑building links, high‑density rack connections | • Cheaper than single‑mode for ≤ 400 m • Easier to terminate (no polishing) | • Bandwidth‑distance product limited – not future‑proof beyond ~400 m |
| OM5 multimode | 40 Gbps / 100 Gbps (and emerging 200 Gbps) | Similar to OM4, but supports wide‑band (850 nm + 950 nm) lasers, giving a bit more headroom | Same as OM4 but when you anticipate upgrades to 200 Gbps in the next 5‑7 years | • Same install‑ease as OM4 • Slightly higher cost, but better long‑term value | • Still limited to a few hundred metres |
| OS2 single‑mode | 10 Gbps up to 400 Gbps (and beyond) | 2 km‑10 km+ (depends on transceiver) | Metro‑wide fibre, long‑haul between sites, future‑proof backbone | • Highest reach and capacity • Small‑core, low attenuation • Best ROI for any link > 500 m | • More expensive cable and termination kits • Requires precision polishing and stricter bend‑radius handling |
When to choose fibre over copper
- Distance > 30 m and you need 10 Gbps or more – copper quickly hits its limits.
- You anticipate future upgrades (40 Gbps, 100 Gbps, 400 Gbps). Multimode OM5 gives you a smoother path.
- The environment is electrically noisy (near heavy machinery, UPS rooms) – fibre is immune to EMI.
- You need high‑density PoE+ over long runs – fibre can carry the data, and you can place a media‑converter/power‑injector close to the endpoint.
3. Certification
Certification is ESSENTIAL and whoever you select to provide the structured cabling MUST provide this. An example certification report is below and you require a report like this for every single cable drop and custom patch. DO NOT be placated with 'summary' or 'certificates' as these mean nothing.
4. Cost‑vs‑Future‑Proof Quick Reference (UK market, 2024‑25)
| Cable | Approx. cost per metre (incl. termination kit) | Typical installation labour | Replacement cycle |
|---|---|---|---|
| Cat5e | £0.30 – £0.45 | Low – easy pull & terminate | 5‑7 years (may need upgrade) |
| Cat6a | £0.55 – £0.80 | Moderate – stiffer, needs careful bending | 7‑10 years (good for 10 Gbps) |
| Cat8 | £1.20 – £1.80 | High – heavy, requires Cat8‑rated tools | 10+ years (but limited to short runs) |
| OM4 multimode | £0.90 – £1.20 | Moderate – simple connector kits | 10+ years (future‑proof to 100 Gbps) |
| OM5 multimode | £1.10 – £1.40 | Same as OM4 | 10+ years (ready for 200 Gbps) |
| OS2 single‑mode | £1.30 – £2.00 | Higher – precision polishing, bend‑radius care | 15+ years (best long‑term) |
Prices are indicative for bulk UK purchases; actual cost will vary with supplier and volume.
Bottom Line
Choosing the right structured cabling solution is a long term decision, and should be considered carefully.
If you need a detailed site survey or a quotation for any of the above options, feel free to get in touch – our engineers can assess the route, advise on the best termination method, and provide a full cost‑benefit analysis tailored to your organisation.
