Pre-Terminated Cabling Systems - Part I
This CTD discusses the properties and advantages of pre-terminated cabling systems, with a particular focus on data center and open office applications. I’ll describe what a pre-terminated cabling system is and what the benefits are in employing this type of solution.
The applicable industry standards are briefly discussed as they drive the type of solutions employed to assure reliability and compatibility. I will also talk about some of the important considerations when planning and deploying a pre-terminated cabling system to help achieve a successful installation. Some of this you may already know, but my objective is to provide you with some useful information to think about when planning and installing pre-terminated cabling systems.
What is a pre-terminated cabling system?
Pre-terminated systems are factory manufactured cables and modular components with connectors already attached that have been tested, qualified and ready to plug-and-play in the network.
Plug-and-play pre-terminated cabling systems can offer significant advantages over field installed system, which is why the use of factory pre-terminated assemblies continues to grow as percentage of total cabling installed, especially for data centers.
The idea of pre-terminated assemblies is not new, however they can come in a number of different forms, from connectorized fan-outs and attached or discreet cassette modules to cable bundles with protective pulling grips installed over the connectors at one end utilizing both fiber and copper cabling.
Data centers continue growing in number and size to meet the demands of today’s increased data storage and application processing requirements. This increased demand for upgraded or new data centers has encouraged the development of alternative concepts for improving the connectivity installation times and simplifying the deployment for advanced reliable and rugged cabling systems within these facilities.
The open office, with its propensity to require a reconfiguration of work spaces on a regular basis, has also benefited from the advantages of alternative cabling concepts that are re-useable or quickly reconfigured to match the moves, adds and changes.
Pre-connectorized cabling continues to gain position in these types of scenarios with gained interest in pre-con assemblies and components. Facilities owners are willing to shift their investment in field installation time to a more “in-front” design with each cabling leg fully specified in advance versus a more determined length and labeling necessary on site.
Benefits of Pre-terminated Cabling Systems
Pre-terminated cabling and components can help manage and reduce costly field termination and testing time as well as decreasing or eliminating cable, connector scrap and the need for field installation consumables.
The plug and play aspects of these systems also facilitates moves, adds and changes and offers rapid re-configurability where and when it’s needed.
Some of the benefits of pre-terminated cabling systems are:
- Rapid Deployment - time savings
- High reliability operation
- Less field testing & troubleshooting
- Consistent quality
- Less waste generation
- Controlled & consistent performance
- Emergency restoration capability
- Company backed warranty
Factory testing of the production assemblies generally guarantees controlled and consistent performance, reliability and overall cabling quality, and is most often backed up by a manufacturer’s warranty of anywhere from 25 years to the life of the installation.
In the case of copper pre-term systems, 100% testing is usually not required. For warranties to be validated, manufacturers generally request from 5% to 10% field testing of the copper trunks being installed.
100% fiber testing is often required because of the issues created by connectors that have dirt, scratches or other contaminants on the connector end-face that compromises network performance. However, issues that can often contribute to time consuming trouble-shooting are minimized as a result of the pre-term cables that are pre-tested directly by the manufacturer and documented and cataloged for future reference.
Some contractors may initially reject the idea of using a pre-terminated solution. Their first reaction might be that it will affect their profitability by reducing the labor required at a particular job site. However, preterm solutions can still be an option for them, in addition to field termination. The decision to utilize one approach over the other for each aspect of the job will most likely will be driven by time and/or resource constraints which can either originate from the customer's requirements or their own. For instance, many times there is very limited access to a data center for security reasons and thus shorter installation times are being allocated by the facilities managers. The contractor then faces either less available job site installation time, fewer technicians may be allowed on site, or sometimes both situations, so they might need a viable option that will allow them to meet an imposed rigorous installation schedule.
With pre-terminated systems, the contractor will be able to meet project deadlines with a smaller staff or similarly, complete more projects with the same size workforce. Not only will the installation be faster but the field testing and troubleshooting can be minimized. Also, pre-terminated assemblies and components that are factory terminated often reduce many of the problems that can occur with field terminations.
Pre-terminated systems also can allow the contractor to make more predictable cost estimates when bidding a job because variables like installation and troubleshooting times are more easily calculated because they are minimized or even negated, and because of less on-site waste to manage and dispose of like excess cable scrap, packaging and materials.
Rapid deployment of pre-terminated emergency restoration systems can be used to mitigate costly downtime & network disruptions, which helps provide piece-of-mind for data center managers.
Cabling & Performance Standards
The TIA, through its foundation 568 commercial cabling standard and referenced standards defines the structured communication cabling design, installation and testing guidelines, which have been embraced and followed in the Americas since the late 1990s. Corresponding structured cabling is also defined internationally by the ISO IEC 11801.
The most significant impacts to copper cabling are in 568.2. Fiber cabling and components are described in the 568.3 section.
The recent publication of TIA-568.3 for fiber is TIA-568.3-D. TIA-568.3-D is not just simply the next revision of ANSI/TIA-568-C.3. In addition to replacing ANSI/TIA-568-C.3 and its ANSI/TIA-568-C.3-1 addendum, it also replaces the some sections of ANSI/TIA-568-C.0 and its ANSI/TIA-568-C.0-1 and ANSI/TIA-568-C.0-2 addenda namely:
- Section 6.4 ("Optical fiber transmission performance and test requirements"),
- Normative Annex B ("MAINTAINING OPTICAL FIBER POLARITY"), and
- Informative Annex E ("GUIDELINES FOR FIELD-TESTING LENGTH, LOSS AND POLARITY OF OPTICAL FIBER CABLING").
At this time, the TIA-942 Data center standard group is working on revision B, and plans to include guidelines in the current draft to consider pre-terminated fiber cables in the data center.
Beside the advantages of helping to assure that the cabling in your data center is installed and tested properly, there are a number of other advantages of following accepted cabling standards that may not be evident such as:
- Interoperability – Standards help to assure that products are manufactured according to specific sets of industry requirements so that they can be used together properly in a system
- Product availability – Standards help maintain consistency across the board from manufacturer to manufacturer so that multiple sources can be established
- Base level performance – Defined specifications for standards compliant products provide added assurance to the customer that those products will consistently meet operational requirements
Be sure to check out Part II about copper solutions in the next release of CTD.