The need for high reliability, along with always required cost efficiency, has established a widely accepted cabling concept in recent years which today is well defined in international standards
EN50173-5 or TIA942. A Data Centre is split into four levels that help allocate the typical
services and applications.

The Client level contains devices like a server – let it be desk top or rack format or even the modern blades – and all kind of storage devices and systems like SAN or NAS, including tape recording devices for backup purposes.

Access switches are situated at the next level, made to couple and connect all devices from client level.

The Distribution level is where routers and layer3 switches operate to make dynamic links between the access level with its aggregated data traffic and the customer applications driven from remote places.

The Core level in a Data Centre forms the gateway with firewall functionality to the group of network service providers connecting the Data Centre to the outside world.

Data Centre Structure.
Here we look at the three main applications enterprises, hosts and carriers.

Enterprise Data Centres
Enterprise Data Centres are considered the power house of IT. It’s where information streams are aggregated and processed in server’s farms, where data are put to storage networks and routed through switches into various other parts of the networks – local and / or global.

Carriers
Carriers, for some time already, are faced with growing demands in added-value services based on content which has to be provided in the most efficient way. The Data Centre cabling standards from TIA and CENELEC can help here as well to deliver valuable planning support and create performing networks utilizing easily available interfaces from the Ethernet family.

Data Centre Hosts
In many cases 500 enterprise clients share their services and in some larger Data Centre hosts even the number of 5000 clients is exceeded. Managed hosting facilities are attractive to businesses because they can rent IT infrastructure instead of investing in it themselves. Servers, networks, applications, bandwidth and other equipment are managed by employees of the facility.

Source: Draka UC Data Cable brochure