Copper Clad Aluminum vs Copper: Testing with the netAlly LinkRunner® 10G

Written by Don Schultz, trueCABLE Senior Technical Marketing Specialist, BICSI TECH, INSTC, INSTF, Fluke Networks Copper/Fiber CCTT Certified

There is a controversial topic that trueCABLE has addressed on numerous occasions in regards to CCA or Copper Clad Aluminum communications (aka “Ethernet”) cable. The debate centers around whether CCA is “good enough”. Experienced structured cabling installers know that twisted pair CCA will not certify to any ANSI/TIA 568 Category standard. That said, will CCA work well enough if not in a high priority corporate or data center environment? What does a cable qualifier think of CCA? We will explore that question using another tool available on the market, discussed below.

Let’s Talk About What Kinds of Tests There Are

When it comes to testing communications cable, you have three levels:

• Verification. Verification is simply verifying continuity and wiremap of your cable + terminations, but this tells you nothing about performance. It is entirely possible for a cable to pass verification and still not pass data well or at all.
• Qualification. Cable qualification takes verification and adds performance data by ensuring the cable will pass Ethernet frames at the appropriate application bandwidth (such as 1000BASE-T) and checks for Ethernet frame errors. This used to be known as BERT or Bit Error Rate Testing. We are testing application speed here and looking for errors; it is not a Category test.
• Certification. Certification requires a test device that measures the communications cable against the actual Category specific ANSI/TIA 568 performance metrics (like Cat6 or Cat6A), performing thousands of complex calculations quickly, presenting the data in decibels (dB) on signal plot graphs and more. The idea here is that any cable that passed Category certification is guaranteed to work at your desired application speed (that the Category supports) under all reasonable conditions.

As you increase the levels of testing, the tester cost exponentially increases.

For those who don’t have the funds or contractual requirement (or both) for a Certification test set like a Fluke DSX-8000, a cable qualification instrument may be what you are looking for. On the market there are two common units, that being the Fluke LinkIQ™ and the netAlly LinkRunner® 10G. In this blog, we will discuss the LinkRunner as it brings a unique feature to the table--the ability to soak (long term) test cabling to run down intermittent and persistent errors that a snap-shot device like the LinkIQ or even an advanced certification test set cannot do.

So, back to the topic of CCA….

What is CCA Cable and Why Is It a Problem?

As mentioned previously, CCA is copper clad aluminum. It is exactly what it sounds like--copper is plated over an aluminum wire. The basic idea is to rely upon the "skinning effect” for data to run over the copper itself and not contact the aluminum and present problems. You see, aluminum is a poor conductor for low voltage electricity. The hook? CCA costs less than pure copper conductor twisted pair Category cable, enticing you to buy it. Why not, right? If it is supposed to give the same results yet costs less, what is not to like? Answer: Plenty.

Here is what CCA looks like inside:

Why CCA is a Problem

• Per the ANSI/TIA-568.2-E - Balanced Twisted-Pair Telecommunications Cabling and Components Standard, Section 5.3, CCA is not allowed and any twisted pair Category cable constructed with it is not TIA compliant
• The NEC/NFPA 70 prohibits the installation of copper clad aluminum twisted pair communications cable--it is literally illegal to install, especially in commercial structures
• Data transmission, long term reliability, and insufficient PoE capability are all issues for CCA

Twisted pair CCA cable pretending to be “Category cable” like Cat5e, Cat6, or Cat6A is hands-down counterfeit cable!

Meet the netAlly LinkRunner® 10G

The netAlly LinkRunner is a test unit designed for use by IT professionals. It is not aimed specifically at cabling contractors who often operate in the field without the benefit of any LAN equipment installed yet. That said, this test device offers some IT specific features and a unique way of testing cable which we will demonstrate!

Key Features of the netAlly LinkRunner® 10G

• Install, test, verify, and troubleshoot Multi-Gig (NBASE-T) and 10G networks using 3rd party apps and purpose-built hardware.
• Supports LANBERT™ Media Qualification testing to quickly validate if your existing cable plant can support higher speeds.
• Layer 1-7 AutoTest helps technicians find network problems, while the periodic test mode monitors networks for intermittent issues, every minute for up to 24 hours.
• Automatically discover devices in your network and generate topology maps* using Link-Live; identifies changes, uncovers security threats, and helps you keep documentation up-to-date.
• Two LinkRunner 10G units can be used to test network performance, capacity, QoS, and service provider SLAs between sites.
• Compatibility with standards-compliant SFPs enables testing and validation of wired media (copper or fiber) for various use cases.

This tester is a popular tool for field technicians due to the plethora of testing capabilities. Of particular note is the LANBERT media qualification which goes beyond quick snap-shop bandwidth qualification to allow for long term testing to run down issues such as those induced by intermittent EMI (electromagnetic interference).

Here are some examples of EMI issues and potential causes that only this tester can bring to light:

Very helpful for running down why your cable has intermittent issues!
Image courtesy of netAlly.

Test Setup

Making use of two netAlly LinkRunner® 10G units and the LANBERT media qualification app on both units, we set up a test to benchmark CCA against solid copper twisted pair Cat6 cable.

Specifics:

• Two LinkRunner units
  • One unit set to generate Ethernet frames
  • One unit set to loopback Ethernet frames
• 295ft trueCABLE Cat6 Unshielded Riser permanent link (solid copper)
• 295ft Brand “X” “So-called Cat6” Unshielded Riser permanent link (CCA)
• Two trueCABLE Cat6 Component Rated 100% Certified patch cords, 6 feet each
• Each test was started at 5GBASE-T, full duplex, as Cat6 supports 5GBASE-T to 328 feet channel distance. If the test did not link at 5GBASE-T, the next lower speed of 2.5GBASE-T was tried and so on.

Please note these are the same links tested in our Fluke DSX-8000 CCA comparison test. Both were tested against the TIA Cat6 Permanent Link +PoE test limit. The CCA link FAILED to Certify (as expected) and the solid copper link PASSED (as expected).

CCA Cable Test Results

Solid Copper Cable Test Results

Analysis: What the Results Tell Us

Test results summary

• Per the TIA standard, any cable calling itself Cat6 should handle 2.5GBASE-T and 5GBASE-T, but the CCA cable cannot get past 1000BASE-T
• It should be noted that even proper Cat5e should handle 2.5GBASE-T. The “Cat6” CCA cable is performing below Cat5e expectations!
• The solid copper cable passes all the way to 5GBASE-T, as it should

trueCABLE has also tested CCA vs solid copper with a Fluke DSX-8000 CableAnalyzer and presented comprehensive results in a blog you can view here: Copper Clad Aluminum vs Copper: The Ultimate Test on a Fluke Versiv DSX CableAnalyzer.

Real-World Implications

So, you might still be thinking about installing CCA. Here are some “on the ground” implications if you should do so:

Practical problems with CCA

• You likely won’t get the speed you expect now and especially in the future
• CCA cable is brittle and not tolerant of bends due to the nature of aluminum, which means conductors are easily broken during installation
• Your terminations WILL fail over time. After termination, the aluminum core of the conductor is not perfectly protected from air exposure. Aluminum is very reactive to the environment and will oxidize quickly. Copper also oxidizes, but when copper oxidizes the resultant copper oxide is highly conductive, where aluminum oxide is not. This will be most apparent on punch down style terminations, where the IDC knives bite into the conductor metal from right angles.
• CCA cable has much higher DC electrical resistance than pure copper which means undervolting of PoE devices, possibly resulting in damage!

Although prohibited for copper twisted pair Category cable, CCA construction is permitted for coaxial communications cable as the aluminum core is not pierced during the termination process. Solid copper coaxial is still the preferred choice, however, due to voltage requirements for satellite systems (at the LNB).

It cannot be overstated that if your installation is commercial in nature, and the local Code Inspector discovers you installed CCA, you will definitely be ordered to remove it! That can hold up occupancy permits, result in fines, and will result in a massive amount of rework!

Conclusion and Recommendations

Copper will always win this battle. Physics dictates that to be so. Aluminum has uses in many applications but twisted pair communications cable is not one of them. Pure copper, while not as good as gold when conducting electrical impulses, is the best metal for the job due to weight, cost, conductivity, and workability.

Please take note when you make a purchase. Do not opt for CCA, but instead opt for solid copper twisted pair Category cable that is safe, effective, and compliant with the standards. Saving a few dollars now will likely cost you many more dollars in the long run! Unfortunately many businesses and homeowners not realizing the risks of CCA have horror stories to tell!

HAPPY NETWORKING!

trueCABLE presents the information on our website, including the “Cable Academy” blog and live chat support, as a service to our customers and other visitors to our website subject to our website terms and conditions. While the information on this website is about data networking and electrical issues, it is not professional advice and any reliance on such material is at your own risk.