RJ45 sockets & workstations

The VDI cabling of an office floor plate simultaneously meets three sets of standards:

• NF C 15-100 for power circuits (30 mA differential protection, article 411.3.3, and permanent conductor identification, article 514);
• ISO/IEC 11801 for low-voltage circuits (maximum length of 90 m between rack and terminal socket, classes E and EA for categories 6 and 6A);
• UTE C 15-900 for coexistence, with a minimum separation of 30 cm between power cables and VDI cables, or the use of dedicated metal shielding.

For the power supply, each workstation requires 4 to 6 16 A earthed sockets (2P+E) protected by a 30 mA residual current circuit breaker. France has 16.8 million office workers, 42% of whom work in open-plan spaces, which gives the reliability of the capillary network a direct bearing on employer obligations regarding occupational health and safety. Kytom applies these three sets of standards on 100% of its projects, with systematic Consuel inspection on new deliveries and B1V, B2V and BR certifications renewed every 3 years in accordance with NF C 18-510.

Our reading differs from the dominant integrator narrative on one specific point: ISO/IEC 11801 compliance is not proven by the cable supply slip but by the link channel certification report, link by link. On 22 projects taken over for renovation, the installed cable was indeed category 6A, but 8 to 14% of links failed the NEXT/Return Loss test due to a lack of care over bend radius and crimping. The standard protects the IT department only if the test is required at the snagging stage.

For the IT department: infrastructure ROI and SLA reading of the capillary network

Reframed from the IT department’s perspective, capillary cabling is not a secondary fit-out item but an infrastructure asset depreciated over 10 years on the balance sheet, with a direct impact on network SLAs and OPEX support budgets.

Three indicators shape the decision:

• Total cost of ownership over 10 years: category 6A cabling installed from the outset is structurally cheaper than a two-stage migration. The initial extra cost is generally absorbed before the end of the first depreciation period, and the 25-year manufacturer system warranty applies from day 1.
• Contractual availability: our link-by-link certification process (Fluke DSX-8000 report) enables the IT department to commit to a capillary SLA with business units, whereas an uncertified estate exposes them to significantly higher failure rates.
• ISO 27001 and GDPR auditability: the digital as-built file delivered within 10 working days (plans, certification reports, schematics, equipment data sheets) constitutes evidence directly admissible during a physical security audit within the meaning of article 32 of the GDPR. The absence of an acceptance test report is a frequent non-compliance point in cyber due diligence.

The Kytom method: 5 steps calibrated over 12 weeks

Our process unfolds in five steps:

1. Technical room audit: locating the main distribution frame, measuring duct lengths, inventorying existing Wi-Fi access points, checking inter-rack OM4 fibre (up to 150 m at 10 Gb/s under ISO/IEC 11801).
2. Sizing: 2 to 4 category 6A RJ45 sockets per workstation, 1 PoE+ socket per 25 m2 in open-plan areas, 4 to 6 earthed sockets (2P+E) per user.
3. Routing plan: minimum 30 cm separation between power and low-voltage circuits, or dedicated metal shielding, in accordance with UTE C 15-900.
4. Installation and connection by B1V and BR certified pairs, using LSZH cable sourced through the branches to secure multi-site lead times.
5. Acceptance and certification: testing of each link channel with an analyser (Fluke DSX-8000 or equivalent), issuing a report per link, 25-year manufacturer system warranty.

For a floor plate of 500 to 1,000 m2 accommodating 70 to 100 workstations, the associated contracted power generally ranges between 50 and 100 kVA, with a scalable reserve sized to absorb future extensions without renegotiating the ENEDIS contract.

Measured benefits on delivered floor plates

Kytom capillary cabling delivers four major gains, observed across all projects delivered over the past three years.

10 Gbit/s scalability

Category 6A handles requirements up to 10 Gbit/s (class EA), giving an estimated useful life of 15 years, compared with 8 years for the legacy category 5e.

Network availability

Our clients observe a very low defective-link rate in the first year thanks to systematic certification, compared with rates several times higher observed on projects taken over for renovation by our teams.

Support productivity

The removal of bandwidth contention points is associated with a noticeable drop in N1 support tickets over the 12 months following delivery, according to ITSM indicators shared by client IT departments.

Budget control

New capillary cabling generally represents EUR 45 to 75 excl. VAT per square metre, i.e. 2 to 4% of the overall fit-out budget, for an asset that can be capitalised on the balance sheet over 10 years. Systematic link certification facilitates information security audits and technical due diligence in the disposal of office assets.

When this approach is NOT the right one. Dense category 6A capillary cabling is not justified below 12 workstations on a residual floor plate set to be vacated within less than 3 years: the ROI exceeds 6 years and a mix of Wi-Fi 6 + 1 backup RJ45 per workstation is sufficient. Likewise, for a fast-turnover coworking floor plate (more than 4 reconfigurations per year), pre-cabling at ceiling level with mobile drops proves significantly cheaper over 5 years than cabling fixed to the floor.