Overview - ISO/IEC TR 11801-9909:2020 and 25 Gbit/s extended reach cabling
ISO/IEC TR 11801-9909:2020 is a Technical Report that evaluates balanced copper cabling for 25 Gbit/s applications with reach greater than 30 metres. It provides non‑normative channel reference implementations based on Category 8.1 and Category 8.2 components (2 000 MHz class) and gives recommendations for achieving extended reach by improving signal-to-noise ratio (SNR) and other channel characteristics. The report is intended as an informative guidance document rather than a mandatory specification.
Key topics and technical requirements
The document examines the full set of balanced‑cabling performance metrics relevant to 25 Gbit/s extended reach, including:
- Enhanced channel implementations (two connections with two 2 m, 20% derated cords; permanent link = channel length − 4 m)
- Important electrical parameters and test items: insertion loss (IL), return loss (RL), near‑end crosstalk (NEXT), attenuation-to-crosstalk ratios (ACR‑N, ACR‑F), alien/exogenous crosstalk (ANEXT), DC loop resistance
- Timing and propagation: propagation delay, delay skew, and methods for reduced delay/delay skew (Annex A)
- Channel balance metrics: TCL, ELTCTL, and coupling attenuation
- Capacity and margin analysis: SNR margin‑to‑capacity and enhanced cable/connector options to increase reach (Annex B)
- Reach ranges explicitly evaluated: ≤ 40 m, ≤ 50 m, ≤ 67 m, and ≤ 100 m
Note: channel and component category specifications in this TR are informative and not normative.
Practical applications and who should use it
This Technical Report targets practitioners planning high‑speed copper deployments where 25 Gbit/s performance beyond standard 30 m limits is desirable. Typical use cases include:
- 25 Gbit/s LANs and high‑performance intra‑building links
- Extended‑reach high‑definition audio/video distribution
- Wi‑Fi access backhaul supporting >10 Gbit/s
- 5G intrabuilding small cell/backhaul cabling
Primary audiences:
- Network designers and system architects
- Cabling manufacturers and connector designers
- Installers, test technicians, and commissioning teams
- Data center and enterprise facility managers
- Equipment vendors validating 25GBASE‑T or similar PHY implementations
Related standards
- ISO/IEC 11801‑1 - Generic cabling general requirements (normative reference for terms/tests)
- ISO/IEC/IEEE 8802‑3:2017/AMD3:2017 (25GBASE‑T) - link segment definitions referenced by the report
- IEC 61935‑1 - Test procedures for balanced cabling (as used for testing in ISO/IEC 11801‑1)
For deployments seeking extended copper reach for 25 Gbit/s, ISO/IEC TR 11801‑9909:2020 is a practical, standards‑based resource for evaluating channel options, trade‑offs, and verification approaches.