ISO/IEC TR 11801-9909:2020/Cor 1:2024

Overview

ISO/IEC TR 11801-9909:2020/Cor 1:2024 is a technical corrigendum to the ISO/IEC technical report that evaluates balanced cabling for supporting 25 Gbit/s links at reaches greater than 30 metres. The corrigendum updates the normative calculation of propagation delay for a 50 m channel by replacing Table 10 with revised, frequency‑dependent formulae. This update refines how Category 8 cabling performance is specified and tested for high‑speed applications.

Key topics and requirements

• Propagation delay specifications: The corrigendum replaces Table 10 with explicit formulae for maximum propagation delay for a 50 m channel. The new formulae are frequency‑dependent and apply across the documented frequency range (notably covering 1 ≤ f ≤ 2000 MHz in the corrigendum).
• Category classifications: The update addresses Category 8.1 and Category 8.2 channel components, clarifying how delay is computed for these high‑performance balanced cables.
• Support for 25 Gbit/s over >30 m: The TR focuses on evaluating whether balanced cabling meets the timing and signal integrity needs of 25 Gigabit Ethernet at extended reaches beyond the more common short‑reach scenarios.
• Test and measurement implications: Laboratories and test procedures must adopt the corrected Table 10 formulae when verifying compliance for a 50 m channel to ensure consistent pass/fail determinations.

Practical applications

• Cabling designers and manufacturers can use the corrected propagation delay formulae to validate cable constructions and component specifications for 25G deployments.
• Test labs and quality assurance teams implement the revised Table 10 in acceptance testing and certification procedures for Category 8 cabling systems intended to support 25 Gbit/s at extended reaches.
• Network architects and enterprise IT teams gain clearer guidance when specifying cabling infrastructure for data centers, high‑performance workspaces, and premise installations requiring 25G connectivity beyond 30 m.
• Procurement and compliance functions use the corrigendum to align tender specifications and compliance checks with the updated standard.

Who should use this standard

• Cabling manufacturers and component suppliers
• Independent testing and certification laboratories
• Network designers, IT infrastructure engineers, and data center planners
• Standards bodies and technical committees working on balanced cabling and Ethernet interfaces

Related standards

• ISO/IEC 11801 series (generic cabling standards)
• IEEE 802.3 Ethernet standards (including 25G Ethernet specifications)

This corrigendum is essential for anyone testing, designing, procuring, or certifying balanced cabling systems intended to reliably support 25 Gbit/s at distances greater than 30 metres - ensuring consistent propagation delay evaluation for Category 8.1 and 8.2 channels.