NEWS

• 2020/9/29 13:28:30

Cat 8 specification has been approved, what should be done next?

There are so many topics around cat 8 that you and your customers may want to know how this will affect the deployment and testing of transport facilities.



Let's start with a little bit of insight into the deployment environment and the key features that affect installation and testing.



Data center only



Cat 8 cabling supports up to 2 GHz, 30 meters away, 2-connector channels, and tends to be data center applications - not likely for LANs. Cat 8 targets data center edge applications, copper connections between servers and switches, which will carry emerging 25 and 40 Gb / s rates.



Although some high-speed direct connect SFP + and qsfp + cables can support such high rates between the switch and the server, these cables have a distance limit of about 5 to 7 meters. Cat 8 is very suitable for more flexible and manageable deployment when the edge switch is at the end of the column or in the middle due to its support for 30 m transmission distance. Because cat 8 shares the same connector and can automatically negotiate with existing business technologies, it has strong interoperability with these technologies.



External crosstalk





Cat 8 cabling is a shielded cabling system, which uses shielded connections and FTP cables. Four pairs of twisted pairs are covered with metal foil. Metal foil shielding is very important to prevent noise from entering the cable or from noise in the cable.



We know that the higher the frequency, the more serious the crosstalk between adjacent cables (i.e. external crosstalk). Therefore, cat 6A standard requires measurement of external crosstalk. The frequency of cat 8 is four times that of cat 6A at 500 MHz, and compliance is still required - all parameters required by the cat 6A standard.



As with cat 6A shielded cables, it should be difficult to see any external crosstalk on cat 8 systems. But like cat 6A shielded cables, they are still required to be tested. Why?



First, cat 8 has more stringent external crosstalk requirements. Secondly, if the installation is not correct, the shielded wiring may fail the external crosstalk test, such as the shielding layer is not connected or the non conducting side is not clamped.



Shielding integrity is critical





If you are not familiar with the deployment and testing of shielded cables, you must be familiar with cat 8. This means that the installers and contractors need to ensure that the cable connector shield is connected carefully and that proper grounding and binding measures are taken.



In the data center, if the copper cable link is connected from the grounding panel of one grounded cabinet to the grounding panel in another grounded cabinet, the open shielding layer may still pass the wiring diagram test. This is because the connectivity of the shield has historically been a DC measurement, and the DC signal will reach the far end unit through a common building site rather than through a cabling link. Therefore, it is difficult to diagnose the cable fault with open shielding layer.





Fortunately, fluke network already has the technology to solve this problem. Only dsx-5000 cableanalyzer Gamma It provides shielding integrity test function and adopts patented AC measurement technology to prevent unconnected shielding layer from showing normal connection due to grounded cabinet in data center.



You are one step ahead in time





Now that the TIA cat 8 specification, component and link limits have been completed, work on the ANSI / tia-1152-a field test standard can be finalized. Fluke network is the leader of the project and the author of the standard, which specifies the field test method and 2G accuracy.



In addition, you have enough time to work on the details of cat 8. At present, there are no cat 8 components shipped and no 25gbase-t / 40gbase-t devices are available. At the same time, fluke network is working closely with leading cabling manufacturers to ensure that you can easily and reliably test its solutions in the field when you start installation.