I have recently test the CAT6 cable from some manufacturer to test the signal quality and performance. It done by do simple 1GByte file download test using 100 Meter and 150 Meter CAT5e/CAT6 cable (connected via patch panel and patch cord like common installation in TIA/EIA 568B structured cabling standard) to see how much frame error occurred. I did not measured with TDR, Signal Analyzer, etc because all cable should conform the spec when tested from factory (or it to be rejected by most customer anyway).
But ... Results is somewhat really surprising, At first, I thought that using 10BASE-T Signal on CAT6 cable should result in longest transmission with no frame lost, and followed by 100BASE-TX and 1000BASE-T.
Actual result is not like that, on 150M CAT6 cable, 10Mbps using 10BASE-T signal doing well and with small numbers of frame lost when transferring 1Gbyte files. 100Mbps on 100BASE-TX signal is very bad with thousands of frame error. And really surprising, 1000Mbps on 1000BASE-T signal is doing good, PAM5x5 modulation plus 8b10b encoding on 1000BASE-T is very reliable and immune to noise, only a few (less than 10) frames are error.
This are numbers of frame error on the cable tested with transferring 1GB file on 150M cable
| Frame error | |||
| Cable | 10M (10BASE-T) | 100M (100BASE-TX) | 1000M (1000BASE-T) |
| CAT5e Brand A | 221 | Unusable | Unusable |
| CAT5e Brand B | 155 | Unusable | Unusable |
| CAT6 Brand A | 0 | 1521 | 7 |
| CAT6 Brand B | 0 | 1422 | 3 |
So ... Installing 1Gbps Switch on CAT6 Infrastructure does some advantage over 100Mbps switch. You can even use 100M+ distance over CAT6 cable, although TIA/EIA 568 recommended CAT6 at 100M, Actual usable distance is up to 150M if the cable is good enough.
Noted that, TIA/EIA 568B.2 AD10 (2008) now updated to have Argumentd CAT6 (CAT6a or CAT6e) for 10GBASE-T Installation for 100M distance but also permit CAT6 for 10GBASE-T if the total length is less than 55M for old CAT6 installation, because CAT6a is expensive and must have twice signal performance characteristics than CAT6 (250MHz vs 500MHz). CAT6a is not probably not the choice to deploy in installation with distance not exceed 55M.
