Cabling Standards

To ensure all devices receive the optimum connectivity and to prevent bottlenecks and differing speed experiences in classrooms around the school, it is critical that up to date industry standard cabling is used.

CAT6 is an accepted industry standard for copper cabling and performs more effectively on networks with higher bandwidths.

All cabling work undertaken should be carefully considered and planned; procured in compliance with national procurement regulations; and installed by professional organisations.

Structured cabling refers to infrastructure cabling within a building and provides the underpinning backbone, and associated elements, that ensure networked devices can communicate with one another easily.

CAT6 copper cable is capable of delivering the higher bandwidths that are encountered on a school IT network. It offers higher performance – supporting networks up to 10Gbps and provides more stringent management of cross talk (electromagnetic interference in the cable pairs).

Schools should be mindful that Education Technology Support Partners are installing quality certified CAT6 cable which is properly shielded and twisted.

There are many known issues and limitations with Universal Twisted Pair (UTP) cabling that uses Copper Clad Aluminium (CCA) rather than ‘pure’ copper cabling to carry the electrical signals in data transmission. To ensure that it is fully fit for purpose in a school environment, any structured cabling must meet full CAT6 certification and not use CCA based cabling. CCA based cabling has poor flexibility and a very poor bend-radius; susceptible to oxidation and corrosion; and not suited to Power-over-Ethernet (PoE) delivery impacting on school IT network performance.

All elements of new structured cabling infrastructure must be Cat 6 for the Standard to be met – including jacks, patch leads, patch panels, cross-connects and the cabling itself.

Certified CAT6 cabling should be used for runs between core and edge switches, servers and wireless access points/controllers but CAT5e cabling could be used for patching from wall sockets to desktop PCs or other network enabled devices such as SmartBoards, SmartTVs, display units etc.

Implementation Guidelines:

The Standard is envisaged as a best practice solution for schools to best meet their digital needs. However, it is accepted that schools are operating on limited resources. Guidelines for attaining the Standard over time could be as follows:

• Current CAT5e cabling should be sufficient when patching from wall sockets to desktop PCs or other network enabled devices such as SmartBoards, SmartTVs, display units
• Certified CAT6 cabling should be used for structured cabling runs between core and edge switches, servers and wireless access points/controllers
• The use of ‘budget’ CAT6 cable that uses Copper Clad Aluminium (CCA) should be avoided due to known limitations and issues with CCA
• Where upgrades to switches and broadband capacity is being considered, then upgrading of the structured cabling should also be considered
• New builds and structured cabling refresh programmes should utilise certified CAT6 cable from a known manufacturer.

Fibre is faster. To ensure teaching and learning benefits from maximum network speeds, fibre cabling is the best option. The latest in industry standard cabling is currently 'OM4' for fibre cables.

Fibre cabling in schools needs to support the flow of network traffic for the length of its connection without compromising the data flow.

Fibre cabling between cabinets in schools should be a minimum of OM4 – this is a multi-mode cable which is optimised to support 10Gbps Ethernet connections up to 400 metres. This should contain a minimum of 8 core fibres in four pairs to allow for these longer reaches, support higher data transfer rates, parallel connectivity and offers resilience and future proofing to the cabling infrastructure.

Shorter runs of up to 150 metres can support data flow of up to 100Gbps.

This supports network traffic without any degradation in service over the length of the connection, reducing pinch points and allowing for greater data management.

It is unlikely that single-mode fibre is necessary within a school environment, even when linking buildings within a school boundary.

Single-mode fibre is traditionally used where longer distances are required (multiple kilometres not tens or hundreds of metres). Additionally, single-mode optical interfaces on school IT network devices tend to be more expensive than equivalent multi-mode optical interfaces.

Where single-mode fibre is already in place, you will need to continue to ‘light’ this using single-mode interfaces as multimode optical interfaces cannot inject sufficient light into a single mode fibre.

The Standard is envisaged as a best practice solution for schools to best meet their digital needs. However, it is accepted that schools are operating on limited resources. Guidelines for attaining the Standard over time could be as follows:

• Highlighting where different cable solutions are appropriate dependent on length of connection and required speeds
• Understanding of overall school IT network topology should support wider knowledge in terms of where OM4 cable exists
• Review of cabling requirements in line with Standard D8 will highlight where and when upgrades to the network are required.

It is easy to overlook, but it is important to ensure that school cabling is tested to meet standards regularly in order to maintain high speed internet access for all classrooms.

Your IT support partner can advise you on testing.

All major structured cabling installations should be tested to ensure that they meet performance specifications for performance.

Prior to sign off, the testing should:

• Follow a documented testing regime
• Record and archive results of structured cabling tests including copies for the school and/or local authority. This will evidence that the structured cabling infrastructure in a school meets agreed industry standards
• It is not necessary to test all network cables – for instance the shorter pre-terminated RJ45 ‘patch’ leads that typically connect a device to a floor or wall plate tend to be manufactured to strict guidelines. To satisfy the school a random selection of pre-terminated patch leads from a supplier cables should be tested to ensure that they meet specification.

Testing protocols and guidelines should be established in conjunction with guidance from the local authority.

Structured cabling between buildings needs to be safely and professionally installed so all learning areas in school receive equivalent and consistent network access.

This ensures that the network capacity is not compromised and also ensures that the school is not compromising any local authority IT specifications or health and safety regulations.

Where schools have connections between buildings, these should be reviewed to ascertain their compliance with the recommendations in this Standard.

All future structured cabling taking place between buildings (whether remedial or for expansion) should follow the guidance above and be:

• Guided by the local authority standards and recommendations
• Professionally installed (ideally by a local authority approved contractor)
• Appropriately contained, terminated and labelled
• Warranted in accordance with local authority guidelines.

Additionally, adequate protection should be given to external cables. For example armoured cable is covered by a metal sheath which protects it from water and extreme temperatures, allowing it to be used in underground or external cable runs.

As outlined in Standard B7, all network access points should be labelled floor or wall boxes.

Cables connected in this way are less likely to cause intermittent connection problems that can disrupt lessons. If labelled clearly, issues can be identified and fixed easily.

This ensures that school IT networks are correctly labelled and that devices have a direct route back into network infrastructure.

Schools should avoid using network extenders or mini hubs as these are unmanaged devices (please see Standard C), and can have significant detrimental impact on the overall network capacity and throughput.

Network points should be consistently labelled across the school and should identify which cabinet and switch the point routes back to.

All network cables should be labelled as they enter the data network cabinet. Intermittent connection problems that can disrupt lessons can be diagnosed, identified and fixed easily, if cables are labelled clearly.

Labelled patch panels in cabinets allow for network staff, or Education Technology Support Partners (ideally local authorities), to identify issues that are arising and also understand which part of the network is being affected. Clearly mapped school IT network topology with labelling and colour coding as outlined elsewhere in these Standards further supports the effective management of the overall network.

You will also need to ensure that you apply labelling conventions consistently across the school so that anyone needing to investigate, or work with the school IT network can easily determine which cables need to be examined.

Cables should be neatly grouped as they enter and leave data cabinets to assist with identification and elimination of any issues that can disrupt lessons.

Clear management of network ports and the links between cabinets should always be supported by clear cable management though designated rails.

The importance of tidy cabinets is even more crucial when additions or upgrades are being made to the school IT network. Clear cable management allows for easy identification of available ports on a switch and which cables are going where in the wider network.

Implementation Guidelines:

• Review status of current cabling in data cabinets
• Ensuring labelling and colour coding standards are in place across all cabinets supporting better understanding of capacity and function
• Deploy appropriate cable management solutions e.g. cable ties.

All cables should be colour coded and of the correct length to assist with identification and elimination of any issues that can disrupt lessons.

Whilst there are no industry standards for colour coding of cables – it would help to allocate colour coding according to function of the cable for example.

Please note this only refers to cables within a patch or comms cabinet.

Patch cables need to be of a sufficient length to avoid data degradation. They will also ensure that the overall management of the network is efficient, and open to being easily understood by personnel other than network management staff.

There is no standard length for patch cables, but you should assume that cables may need to accommodate additional equipment at some point in their lifecycle. Therefore making them too short could impede flexibility.

Although there is no standard allocation of colours for network cables, it would be useful to group cable colours by function: for example – yellow for VOIP, white for patch cables, blue for core switching etc. As long as this is documented in the network topology documentation, it will allow for common understanding by any other network professionals. This should be consistent across all cabinets in school and included with the network documentation.

Cable routing should be reviewed regularly to ensure it is aligned with plans for expansion or aspirational usage.

Cables may need to be re-routed now to best accommodate any future learning space developments.

Cable installations should be subjected to periodic inspection and testing, according to local authority guidelines. As a guideline all installations should be checked at five years after installation, and every 3 years after this.

Checking involves testing a sample of the cabling in school to ensure that there is no degradation of service across the cable. This should be done in accordance with Standard D2, and the results of these checks should be documented and archived.

Testing protocols should be established in conjunction with the local authority.

To comply with health and safety regulations, all school cabling should conform to BS7671.

This ensures the correct cable material is used and fire resistance is planned for during installation.

Steps that can be taken to address the need for containment include:

• Review current status of containment and any potential issues within cabinets and comms rooms; and
• Extensions to school IT network infrastructure, upgrades to switches or cabling etc should include plans for containment in comms rooms as part of the overall project planning.

Where possible, you should consider using Low Smoke Zero Halogen (LSOH) cable where the coating on the cable burns more slowly; haslower smoke emission; and no halogen emissions. This makes evacuation easier in case of a fire.