| Full title | Information technology. Generic cabling for customer premises. Part 2: Office premises |
| Publisher | ISO and IEC, prepared by ISO/IEC JTC 1/SC 25 |
| Current edition | Edition 1, November 2017, with Corrigendum 1:2018 |
| Status | Published and current. No amendment listed. |
| Replaces | ISO/IEC 11801:2002 and its Amendments 1:2008 and 2:2010 (together with ISO/IEC 11801-1) |
| European counterpart | EN 50173-2:2018, published in the UK as BS EN 50173-2:2018 |
What it covers
ISO/IEC 11801-2 specifies generic cabling within and between the buildings of office premises. It also applies to office spaces inside other types of building. It is optimised for premises where telecommunications services are distributed over a maximum of 2 000 m.
It covers balanced cabling and optical fibre cabling. It specifies the structure of the cabling, the telecommunications outlet interfaces, channel and link performance, reference implementations, and the requirements for cables, connecting hardware and cords.
It holds only the requirements specific to offices. The common requirements, including class limits and backbone cabling, are in ISO/IEC 11801-1. Other premises types have their own parts:
- industrial spaces: ISO/IEC 11801-3
- homes: ISO/IEC 11801-4
- data centre spaces: ISO/IEC 11801-5
- distributed building services: ISO/IEC 11801-6
Structure of the cabling
The cabling is a hierarchical star with three subsystems: campus backbone, building backbone and horizontal cabling.
| Element | Role |
|---|---|
| Campus distributor (CD) | Distributor for the campus backbone, typically one per campus |
| Building distributor (BD) | Distributor for the building backbone, typically one per building |
| Floor distributor (FD) | Distributor from which horizontal cabling runs to the outlets |
| Consolidation point (CP) | Optional connection point in the horizontal cabling between the FD and the TO |
| Telecommunications outlet (TO) | Fixed outlet in the work area where horizontal cabling ends |
| Multi-user telecommunications outlet (MUTO) | Grouping of TOs serving several work areas |
The horizontal subsystem runs from the FD to the TOs. It includes the horizontal cables, their terminations, the cords or jumpers at the FD, and any CP with its CP cable. The standard also covers centralised cabling, combined BD and FD arrangements, and redundancy.
Horizontal reference implementation
The reference implementation sets a maximum horizontal channel length of 100 m. The usual split is up to 90 m of fixed horizontal cable plus up to 10 m of cords in total. The standard gives horizontal link length equations, so longer cords mean a shorter permitted fixed cable.
| Item | Value |
|---|---|
| Maximum horizontal channel | 100 m |
| Typical fixed horizontal cable | Up to 90 m, with 10 m of cords |
| Horizontal plus building and campus backbone | 2 000 m |
The models cover a channel with and without a CP.
Classes and components
ISO/IEC 11801-2 adopts balanced cabling channel and link Classes E, EA, F and FA from ISO/IEC 11801-1.
| Media | Recognised in EN 50173-2:2018 |
|---|---|
| Balanced cable categories | 6, 6A, 7, 7A, 8.1 and 8.2 |
| Cabled optical fibre categories | OM3, OM4, OM5, OS1a and OS2 |
Minimum configuration in EN 50173-2
- At least one TO in each work area.
- The first TO terminates all four pairs of a balanced cable, or optical fibres.
- Further TOs should terminate four pairs. Two pairs per TO are allowed under stated conditions, with the pair assignment recorded.
- There should be at least one FD for every 1 000 m² of office floor space and at least one FD per floor. A sparsely occupied floor, such as a lobby, may be served from the FD on an adjacent floor.
How it relates to other standards
- EN 50173-2:2018 is the European counterpart, approved by CENELEC in March 2018. It supersedes EN 50173-2:2007+A1:2010+AC:2011. It added cable Categories 8.1 and 8.2 and fibre Categories OM5 and OS1a. BSI publishes it as BS EN 50173-2:2018, which supersedes BS EN 50173-2:2007+A1:2010.
- ISO/IEC 11801-1 and BS EN 50173-1 hold the class limits, component categories and backbone requirements that this part refers to.
- ANSI/TIA-568.1 is the North American commercial building standard. It uses its own terms, such as horizontal cross-connect and telecommunications outlet.
- BS EN 50174-1 and -2 cover installation planning and practice.
What it means in practice
- Name the CD, BD, FD, CP and TO on drawings so the design can be checked against the standard.
- Allow for the usual split of up to 90 m of fixed horizontal cable with 10 m of cords. Use the length equations if cords will be longer.
- State the channel class (for example Class EA) and the cable category (for example Category 6A) separately. Classes apply to channels and links; categories apply to components.
- Field test the permanent link or channel against ISO/IEC 11801-1 class limits where ISO/IEC 11801-2 or EN 50173-2 is the contract standard.
- Check the corrigendum is included when quoting the ISO edition.
Related reading: What is structured cabling? · The complete guide to Cat6A cable.