This is a continuation of Part I. Since the last write up I have obtained followings:
- TrueCable recommended Keystone Jack (10GTek)
- Replacement spool of Cat 6 Cable
- Fluke MicroScanner PoE
- Previous Cable Spool Test Result by Fluke Certification Tester
Background
In quick summary, I have recently been working on setting up 10G home network infrastructure in my 1950’s built old home. Although I have had some devices capable of supporting 10G network including Qnap NAS and Mac mini 2018, I had never tested this potential. Now with erupting interest in 10G network, I have purchased Thunderbolt 3 to 10G RJ45 Ethernet adapter. With this I have started to previously installed Cat 6 cables throughout my home which successfully showed 10G speed with iPerf even on the longest distant cable. So I’ve decided to add 4 more cable runs in my home, but with this I have encountered an issue that newly installed cables weren’t performing at 10G capacity despite what I considered physically shorter length cables than previous install and using the identical brand, same model Cat 6 cable. After multiple attempt of fixing including re-termination of cables with different keystones including TrueCable recommended Keystone Jack (10GTek), I was able to achieve only the following at the best.
Cable Testing
MicroScanner PoE
Fluke MicroScanner PoE
I have had $10 continuity cable tester to ensure each pairs of cables are in continuity. All newly installed 4 cables passed this test. After multiple tests with different configuration e.g. changing client device, patch cable, switch, my suspicion grew higher and higher towards the newly installed long Ethernet Cables.
So I have decided to purchase $600+ Ethernet Cable Verifier, Fluke MicroScanner POE. You can read my full review about this device here. The device confirmed all four cable runs are indeed less shorter than the longest cable I had (154ft) with the longest from current installation measuring 137 ft. The verifier tester showed no issue.
Certification Test
Cable tester device may be divided into 3 kinds: verification, qualification and certification (ref). As it turns out, despite 60x the price from my original cable tester, Fluke MicroScanner POE still falls under the same category i.e. verification tool. These tests if the cable is connected correctly. However, it does not measure actual throughput of the cable, which needs qualification tool or perform iPerf type of testing. As the tester grading becomes higher, so are the price. The highest level test tool, certification tool costs ~$10,000 range. These tools test if the cable comply with the cable standard.
TrueCable requested/offered to test the spool of cable I have recently purchased using certification graded Fluke tester as to see if the cable has any issue.
The result here is obvious, the cable failed all 3 tests they conducted. Supposedly, the last test is to see if the cable works at all. Because certification tester is higher grade, much higher priced testing tool, there is no question which one to trust here especially I know these cable not producing expected performance. The surprise/disappointment here is $600+ verifier tester could not catch any issue on the cable despite complete failure of the cable on certification tool. Basically, it clearly shows not all testers are made equal even for to answer what seems a simple question of “does this cable work?”
not all testers are made equal even for to answer what seems a simple question of “does this cable work?”
Follow up
I got a really bad luck/TrueCable must have really poor quality control, it turned out my replacement spool also had the same issue. Fortunately, this time I caught it before all 4 runs were installed i.e. I asked the installer to start with a first/longest run so I could test the speed and make sure the cable is functioning. I had separate cable that I purchased last year so I had my installer use that cable instead and as expected, I was able to achieve 10G up and down on iPerf test immediately.
Learning Points
- Patch cables may affect throughput when part of long distance run even if the patch cable itself could pass 10G at short distance.
- Not all cable testers are made equal.
- Cheap including $600 Fluke MicroScanner POE tester may not catch all the issues on ethernet cable
- Unshielded Cat 6 can support 150+ft (rated for 55m/180ft)
Recommendation
- Unshielded Cat 6 may still be a good option for under 55m/180ft cable run in 10G network.
- Test cable speed with iPerf, ideally at 10G.
- Be sure to test the cable (the longest run ideally) before proceeding with others if installer is doing the job with cost charged per line to ensure the cable is NOT defective
- When in doubt, consider following troubleshooting:
- Change patch cable (the best one I have seems like Cat 7 rated even though I do not have Cat 7 patch panel, keystone
- Change Keystone