| Full title | Information technology. Generic cabling for customer premises. Part 1: General requirements |
| Publisher | ISO and IEC, prepared by ISO/IEC JTC 1/SC 25 |
| Current edition | Edition 1, November 2017, with Corrigendum 1:2018 and Amendment 1:2025 (and its Corrigendum 1:2025) |
| Status | Published and current |
| Replaces | With ISO/IEC 11801-2, it cancels and replaces ISO/IEC 11801:2002 and its Amendments 1:2008 and 2:2010 |
| Related standards | ISO/IEC 11801-2 to -6, EN 50173-1, ANSI/TIA-568.2, ANSI/TIA-568.3 |
What it covers
ISO/IEC 11801-1 specifies the requirements that are common to the other parts of the ISO/IEC 11801 series. It describes a multi-vendor cabling system that supports voice, data, video and power delivery. It does not contain conformance requirements of its own. Those sit in the premises parts.
The scope covers:
- structure and configuration of generic cabling
- channel transmission, environmental and power delivery performance
- link performance
- backbone reference implementations
- component requirements
- test procedures
The ISO/IEC 11801 series
| Part | Title | Previous document |
|---|---|---|
| 11801-1 | General requirements | ISO/IEC 11801 |
| 11801-2 | Office premises | ISO/IEC 11801 |
| 11801-3 | Industrial premises | ISO/IEC 24702 |
| 11801-4 | Single-tenant homes | ISO/IEC 15018 |
| 11801-5 | Data centres | ISO/IEC 24764 |
| 11801-6 | Distributed building services | New |
The 2017 restructure brought the international series into line with the structure of the European EN 50173 series.
Changes in the 2017 edition
- Re-structured to hold only the elements common to all generic cabling
- Balanced cabling channel and link Classes BCT-B, I and II added
- Coaxial cabling channel and link Class BCT-C added
- Balanced component Categories BCT-B, 8.1 and 8.2 added
- Cabled optical fibre Categories OS1a and OM5 added
- Optical fibre classes (such as OF-300 and OF-500) removed
- OM1, OM2 and OS1 moved to an informative annex
Amendment 1:2025
Amendment 1 (November 2025) adds single pair component Categories T1-A, T1-B and T1-C, and channel and link classes with the same names. Single pair cabling is intended for devices such as sensors, actuators and controllers in intelligent buildings and industrial automation. It does not replace 4-pair cabling.
The amendment also corrects the 2017 text, adds power delivery to the scope wording and adds references including ISO/IEC TS 29125 for remote powering and IEC 63171 for single pair connectors.
Classes and categories: ISO and TIA names
ISO uses classes for channels and links and categories for components. Some ISO category names differ from TIA names for similar performance.
| ISO class | Specified up to | ISO component category | Nearest TIA category |
|---|---|---|---|
| Class D | 100 MHz | Category 5 | Category 5e |
| Class E | 250 MHz | Category 6 | Category 6 |
| Class EA | 500 MHz | Category 6A | Category 6A |
| Class F | 600 MHz | Category 7 | Not recognised by TIA |
| Class FA | 1 000 MHz | Category 7A | Not recognised by TIA |
| Class I | 2 000 MHz | Category 8.1 | Category 8 |
| Class II | 2 000 MHz | Category 8.2 | No TIA equivalent |
The standard also keeps the low-frequency Classes A (100 kHz), B (1 MHz) and C (16 MHz).
“Category 5e” is a TIA name. In ISO/IEC 11801-1 the components used for Class D are called Category 5.
Classes I and II
Classes I and II support 25GBASE-T and 40GBASE-T. The channel is limited to 30 m with no more than two connections. Category 8.1 components use the RJ45-style modular interface and are backward compatible with Class EA. Category 8.2 components use higher-performance shielded interfaces. Some, such as IEC 60603-7-82, are backward compatible with RJ45. Others, such as IEC 61076-3-104, are not.
BCT classes
Class BCT-B (balanced) and Class BCT-C (coaxial) support broadcast and communications technology (BCT) applications.
Cabled optical fibre categories
| Category | Type | Effective modal bandwidth at 850 nm |
|---|---|---|
| OM3 | Multimode 50/125 µm | 2 000 MHz·km |
| OM4 | Multimode 50/125 µm | 4 700 MHz·km |
| OM5 | Multimode 50/125 µm | 4 700 MHz·km, also specified at 953 nm |
| OS1a | Single-mode | Not applicable |
| OS2 | Single-mode | Not applicable |
OS1a and OS2 are both specified at 1 310 nm, 1 383 nm and 1 550 nm. OS2 has the lower maximum attenuation and is the usual choice for longer runs.
How it relates to other standards
- EN 50173-1:2018 is the European equivalent, with the same class and category names. In the UK it is published as BS EN 50173-1.
- ANSI/TIA-568.2 covers twisted-pair components and cabling in North America. TIA Category 8 corresponds to ISO Class I with Category 8.1 components.
- ANSI/TIA-568.3 covers optical fibre cabling and components and uses the same OM and OS names.
What it means in practice
- When a specification calls for ISO/IEC 11801 compliance, check that components are rated to the ISO category, for example Category 6A to ISO/IEC 11801-1, not only to a TIA category.
- Check that field test reports use ISO class limits (for example Class EA permanent link) where ISO is the contract standard.
- Do not specify optical fibre classes such as OF-300. Specify the cabled fibre category and the application.
- For short data centre links at 2 000 MHz, confirm whether Class I (RJ45-style) or Class II (Category 8.2 interfaces) is required.
Related reading: Cat5e vs Cat6 vs Cat6A: which cable is right? · OM4 vs OM5 fibre: what’s the difference?.