What do those little marks really mean?
Compliance marks on cabling products denote protection that not only helps safeguard data, communications, and corporate brands, but your reputation as well. Marks of compliance ensure that products and systems you're specifying and installing will perform as promised under real-world conditions and meet applicable product safety standards.
Once a product has passed a testing and certification agency's required product safety and/or performance tests, the manufacturer has the right to affix the agency's proprietary mark to the product. These marks, such as UL, CSA, and ETL, are physical proof of a product's compliance to applicable standards. By fully understanding the marks (and the standards and pre-market testing regimen behind them), you can mitigate risks associated with compromised safety and performance.
Marked for safety.
A manufacturer will typically have cabling equipment tested to specific product safety standards that allow the product to be sold in particular markets or used for specific applications. If the product meets or exceeds the requirements of the product safety standard(s), the manufacturer can label it with a “Listed” mark. In addition to the Listing mark, other identifiers outlined by the standard in question act as guides for installation and proper use. The 2002 NEC includes a list of abbreviations for cables, ranging from multipurpose plenum cable (MPP) to undercarpet communications wire and cable (CMUC).
Agencies, such as the Underwriters Laboratories and ETL SEMKO, test products under conditions that simulate a product's intended environment and use. For example, a communications cable intended for use in a plenum is subject to National Fire Protection Association (NFPA) 262: Standard Method of Test for Flame Travel and Smoke of Wires and Cables for Use in Air-Handling Spaces. To measure compliance of a plenum-bound cable, a test lab will replicate fires in a test facility, enabling technical staff to determine the rate at which the cabling product will accelerate a fire and the smoke density of its emissions. Compliant products — those with low fire potential and a low “smoke developed” index as prescribed by the standard — merit usage of the appropriate Listing mark and identifier (MPP or CMP). In this scenario, by knowing what the Listing mark and associated identifiers represent, you can determine if a burning cabling product will perpetuate flame spread scenarios and/or create hazardous smoke conditions in plenums.
Country-specific identifiers, such as US and C, may also be affixed with listing marks to show that the product complies with American and/or Canadian product safety standards, respectively. If you're confused as to what a mark means, most testing and certification organizations provide searchable, online directories for product, company, and standard nomenclature data.
Marked for performance.
While product safety testing is a mandatory evaluation of a cabling product to national consensus standards, performance testing is a voluntary process designed to accomplish one or more of the following goals:
Measure compliance to industry or association criteria.
Substantiate a manufacturer's claims.
Verify capacity of legacy installations.
Performance testing programs provide you with verifiable proof of a product's ongoing quality and performance. When that product is a cable, you get proof of its bandwidth and capacity levels.
Testing a cable's parameters for insertion loss, near-end cross talk (NEXT), return loss (RL), and equal-level far-end cross talk (ELFEXT) falls under the purview of testing to association or industry standards. Among the more notable standards are those published by TIA/EIA, ISO/IEC, and NEMA. If a cable meets the requirements of the industry and/or association standard(s), it may be included in what's known as a verification program and will bear a “verified” mark. However, to ensure the manufacturer is maintaining expected levels of quality and performance, a field representative of the testing and certification agency will visit the manufacturing location at regular intervals throughout the year to select random product samples to test for ongoing compliance. If a product fails one of these evaluations, it may be removed from the verification program.
To protect the investment made in a cabling infrastructure, you may look for cabling systems designed to support multiple generations of networking. Purchasing products independently tested and verified to meet manufacturers' performance claims can help. Several distributors add value at this point by partnering with an independent testing lab to evaluate whatever requirements the distributor wants to ensure the products will meet. This gives you assurance the products perform as claimed.
One distributor, for example, has a program called Verified Independently for Performance (VIP). This distributor verifies that the cabling products it distributes exceed the bandwidth performance requirements of TIA/EIA and IEEE standards for both Cat. 5e and Cat. 6 cabling systems. All products in the VIP program are first evaluated in a lab setting by ETL SEMKO to determine if they meet the program's extended bandwidth performance requirements. Later, the test agency randomly selects products from the distributor's inventory on a quarterly basis to evaluate them for ongoing compliance.
To ensure that existing network systems can perform against increasingly demanding high-speed, high-bandwidth needs, some testing laboratories offer a field verification program. If a company upgrades its network to Fast Ethernet or Gigabit Ethernet (100 Mbps to 1,000 Mbps), such a program will help determine if the cabling and various connections already in place can handle the new bandwidth requirements. In this scenario, the cabling infrastructure must be up to spec, whether it's a simple connector or a complex routing system. One bad link or channel means bandwidth of a cabling system could be the bottleneck to the flow of information and data. The bad link or channel could even bring down a system.
Field verification may also determine if the cable run meets the installation guidelines set forth in commercial building telecommunications wiring standards, such as TIA/EIA-568A or ISO/IEC 11801.
The future of cabling marks and testing.
Just a few years ago, communications cables designed for computer networks were tested to speeds of only 100 MHz. Today, installers are testing cables at 600 MHz and even higher. As the pace of technology quickens, new performance specifications constantly emerge to ensure cables continue to live up to the expectations of end-users.
You can improve the quality of your installations and pave the path for broader bandwidths by knowing what's behind wire and cable marks. These marks tell the story of the application environment and give insight into how well a product will handle a given task. To make sure you've got the right product for the job, check the certification marks — they'll tell you what you need to know.
Nicholson is the general manager of ETL SEMKO's global cabling products testing team, Cortland, N.Y.