A new effort is underway to develop a standard for network distribution nodes (or data centres) -- one which involves very specific requirements and challenges.
December 1, 2001
A new working group on “network distribution nodes” was formed at the June meeting of TIA Engineering committee TR 42 held in Providence, RI. This effort is very important to the industry — for a variety of reasons.
Network distribution nodes, more commonly called data centres, include Internet data centres, service distribution nodes and storage area networks (SANs). These spaces have been recognized as critical to the deployment of a number of next generation standards, which are under development by IEEE and Fiber Channel.
The new working group, which is co-chaired by Chris Diminico of CDT and Mark Maloney of Ehvert Engineering Services, says the initial project on data centres should be completed within 24 months. The scope of the group’s work will include cabling topology, performance and other aspects of the IT infrastructure that will enable these facilities to rapidly deploy emerging technologies such as 10 Gb/s networks. Requirements will consider the need for flexibility, scalability, reliability and space management.
WHAT IS A DATA CENTRE?
So, what are data centres? Data centres are facilities that provide the network infrastructure to give customers access to high-speed MAN and WAN connections, databases, SANs, web-hosted Internet applications, Internet Service Providers (ISPs), e-business, and so on. Data centres are to data traffic what central offices are to voice traffic.
There are two types of data centres: corporate and institutional data centres that are operated by internal IT organizations, and Internet Data Centres (IDCs) that are operated by Internet Infrastructure Services (IIS) providers. The former type is used for equipment consolidation/centralization, Internet/Intranet presence, Web presence/ e-business, storage networks and application integration. The latter type of data centre is used for hosting IIS Internet interconnection and services, including Web presence, storage services and application software.
Data centres provide the physical environment necessary to house the active and passive networking components and allow accessibility and reliability 24 hours a day, 7 days a week, all year around. Redundant and multi-path data cabling, as well as redundant power distribution, provide a fault-tolerant and reliable operational environment.
The topology of a data centre is illustrated in the figure below:
Data centre designs must be planned with specific requirements that include HVAC temperature control systems with separate cooling zones and seismically-braced racks. The designs should also include advanced security features, smoke detection and fire suppression, motion sensors, secure access, video surveillance and security-breach alarms.
There are a number of challenges in designing data centres. Space is an important consideration because of the high cost per square foot to provide all of the required services. The high concentration of equipment makes the high-density cabling structures difficult to manage and control.
Traditional data centres have been raised floor environments because of the ease of cable placement and the aesthetics. Today, the trend is to eliminate the raised floor and go overhead because it is more cost-effective — and this raises many new challenges.
THE CABLING INFRASTRUCTURE
Cabling found in data centres includes unshielded twisted-pair copper cabling and single mode or multimode optical fiber cabling. Some shielded twisted-pair cables and coaxial cables may also be required. With the increasing demand for bandwidth, optical fiber is becoming the leading cabling system used.
A high-speed SAN, separate from the LAN, enables connectivity between the servers and storage devices. Fiber Channel technology and 50-micron glass serve as the data link level transport. Other transport methods (i.e., Gigabit Ethernet) are being evaluated and/or standardized.
Many high-density copper and fiber cable assemblies are also used, including the MPO connector (12 fibers terminated in a single ferrule) and some propriety connectors (e.g. ESCON).
At the next TIA meeting, which will be held in Dallas in November, five contributions will be presented on the design aspects and requirements for data centres. CS
Paul Kish is Director of IBDN Systems & Standards at NORDX/CDT in Pointe Claire, PQ. He is also Chair of the TR-42 engineering committee.
Disclaimer: The information presented is the author’s view and is not official TIA correspondence.