Qualification vs certification

Cable installers and network technicians are expected to cost-effectively demonstrate that their data cabling is installed correctly and is capable of supporting ethernet applications. With a wide array of testers on the market purporting to do similar things, and some just a fraction of the price of others, it’s difficult to determine the best way to test your network. In this article, Michael Florence, Business Development Manager, TRIO Test and Measurement, provides insights on choosing the right cable test tool to ensure the data communication cabling is working capably.

Depending on the requirements, a technician will need to test the cable with at least one of the following devices: certifier - sweeps a frequency range of a cabling link to determine if it meets the requirements of the standards defined by TIA and ISO; qualifier - places ‘real world’ performance demands on a cabling link in order to prove the ability to support ethernet and gigabit applications.

Certification

Certification is the process of measuring high-frequency electrical properties of a cabling link to determine if it meets the requirements of Category 5e, 6, & 6a or ISO’s Class D, E, Ea, F, Fa performance as defined by the TIA/ISO standards.

It is like testing the structural capability of your cabling ‘highway’. When a datacom contractor certifies a cable to a TIA/ISO standard, it is assumed that testing to Cat5/6/6a/7 standards is specifically to test the capability to run IP traffic. While this is often the case, certification of a cable link ensures many other types of data and networking protocols can successfully operate on the certified network.

Certification measures the physical layer of the cable. Depending on the standard, a certifier will test a multitude of parameters (eg, NEXT, return loss, insertion loss, delay skew) and derivative calculations based on these parameters (eg, ELFEXT, PSNEXT, ACR) to a specific frequency defined by the standard. The certifier must also comply with TIA/ISO Level III, Level IIIe, and Level IV accuracy requirements. Cabling contractors, who install or upgrade structured cabling, use certifiers in order to certify their results for warranty purposes.

Some testers (qualifiers) available on the market are sold as ‘certifiers’ to confuse potential buyers into thinking that they are getting the capabilities of a certifier at a fraction of the price. To test copper, a certifier must measure all parameters of the TIA-568-B or ISO 11801 specification and meet Level III, Level IIIe and Level IV accuracy levels.

Many cable and connectivity manufacturers offer installation warranties on their cabling systems. For these warranties to be honoured, the installer must be approved (attend manufacturer-specific training) by the system manufacturer and must certify the cabling system with a true cable certifier such as the Ideal Industries LanTEK II. Certifiers are most often used by cabling contractors who are installing or upgrading structured cabling in order to certify their results for warranty purposes.

Qualification

Qualification is the method of testing that does not measure the electrical characteristics of the cable but uses other performance testing characteristics in order to determine the link and performance capability. While certification ensures capabilities of the cabling for a wide variety of data and networking protocols, qualification specifically runs tests relative to IP networks. It is a cost-effective way to demonstrate that the cabling is installed correctly and capable of supporting ethernet applications without certification. Many qualification testers allow technicians to isolate cabling problems from networking problems. They also allow technicians to identify and troubleshoot a wide range of problems within the network infrastructure.

An interesting and beneficial characteristic of qualifiers is that due to the fact that they run tests higher than the physical layer, they are not limited to testing one type of physical media. For example, the IDEAL Industries SignalTEK II FO tests copper and fibre links to one standard (IEEE 802.3ab) with one device, with no requirement for expensive aftermarket fibre adaptors. The unit uses the type of SFP modules found in a standard networking switch. The device is a full copper and fibre (MM 850 nm, SM 1310 nm and SM 1550 nm) tester, testing to an international IEEE standard for one-fifth of the price of a certification device.

Conclusion

Qualification testers cost significantly less than certification testers. But a qualification tester can’t be used to test cabling for the purpose of providing system warranties. If there is a requirement to provide test data for warranties, certification is the only option. Saying that, more than 80% of new cabling being installed does not require certification testing because most of the volume of newly installed cabling is going into smaller projects such as retail, small commercial and residential installations. Qualification testers are suitable for these jobs because they ensure confidence in the performance of the finished system and provide documentation of performance to the end user.