S 2.396 Specifications for documentation and labelling of IT cabling

Initiation responsibility: Head of IT

Implementation responsibility: Head of IT

If it is planned to replace or modernise the IT cabling, the customer and the contractor (network planner, suppliers, and installers) must agree on how to document the IT cabling. The customer must ensure that he or she has internal and external documentation of the cabling during initial start-up.

The internal documentation consists of all drawings relating to the installation and operation of the IT cabling. The internal documentation must be comprehensively produced and maintained in such a way that operations and future further development are provided with the best possible support.

The external documentation consists of the labelling of connections to provide operational support. To help protect against sabotage and other malicious attacks, as little externally visible documentation (e.g. the labels on the network connections and ends of cables) as possible should be applied to the cabling. In this case, a potential attacker should be given as little information as possible while at the same time still providing the IT personnel with the labels necessary for proper and verifiable patch and network tasks.

For middle- and large-scale cabling projects, the use of suitable software for documentation purposes is absolutely necessary. For this reason, specifications of the file formats, and therefore of the programs and software versions to be used, must also be provided. This ensures that the contractor is able to deliver his/her documentation in a form that can be used immediately by the customer. Likewise, the naming convention for the file names and for the names of elements and structures written in the file should be specified. The version of a file should be recognisable from the file name, for example by starting all file names with date information in the format YYYYMMDD.

Clear naming convention rules and rules for labels used in the documents must also be specified. For example, it must be agreed upon how different classes of routed copper cables must be labelled in drawings (example: L123-cu6a = cable 123, copper, CAT 6a).

One problem often results in the field of room numbers: the architect normally assigns these during the planning phase. These room numbers are also used when planning and installing the IT cabling. If the user of the building introduces a new system for identifying and numbering rooms after moving into the building, this may lead to confusion, impairment of operations, or other security problems.

For example, it may happen that cables are connected to the wrong rooms and therefore between the wrong IT systems due to inconsistent room numbering.

The first step when documenting the IT cabling is the planning and installation documentation. The network topography planned is documented first. The paths planned to be used for the cables and cable trays, as well as the locations of the connection sockets are drawn in the building and room plan in this first step as well. The installer must then produce documents detailing the execution of the cabling work.

The documentation of the IT cabling consists of:

This documentation forms the basis and is an integral part of the principal's acceptance process for the work performed.

It is useful when operating the network later to create one document for the description of the current state of the network and a separate document for later updates. It is only useful to stick to the building plan and to the programs and file formats typically used in building planning (CAD) during the installation phase.

During actual operations, it is more practical to emphasise the logical and IT-specific structures of the IT network in the documentation and place less emphasis on constructional aspects. "IT-related" software tools are more suited for this purpose. The employees are more familiar with the operation of these types of programs than with the operation of CAD software.

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