There are many topics around CAT 8, and you and your customers may wonder how this will affect the deployment and testing of transmission facilities.

We first have a little in-depth understanding of its deployment environment, as well as the key features that affect installation and testing.

Only applicable to data centers

Cat 8 cabling supports up to 2 GHz, a distance of 30 meters, and 2 connector channels, which tend to be used in data center applications—not likely to be used for LANs. Cat 8's target market is data center edge applications, copper cable connections between servers and switches, which will carry the emerging 25 and 40 Gb/s rates.

Although some high-speed direct-attach SFP+ and QSFP+ cables can support such high speeds between the switch and the server, these cables have a distance limit, which is limited to about 5 to 7 meters. Cat 8 supports a transmission distance of 30 meters, so it is very suitable for more flexible and manageable deployment when the edge switch is at the end of the row or in the middle position. Since Cat 8 shares the same connector and can automatically negotiate with existing business technologies, it has strong interoperability with these technologies.

Alien crosstalk

Cat 8 wiring is a shielded wiring system, that is, shielded connections and FTP cables are used, and four pairs of twisted pairs are covered by metal foil. Metal foil shielding is essential to prevent noise from entering the cable or preventing noise in the cable.

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

As with Cat 6A shielded cables, it should be difficult to see any alien crosstalk on a Cat 8 system. But like Cat 6A shielded cable, it is still required to be tested. Why?

First, Cat 8 has stricter alien crosstalk requirements. Secondly, if the installation is not correct, the shielded wiring may not pass the external crosstalk test, such as the shielding layer is not connected or the non-conducting side is not clamped.

Shield integrity is critical

If you are not familiar with the deployment and testing of shielded cables, you must be more familiar with Cat 8. This means that the installer and contractor need to ensure that the cable-connector shield is connected carefully, as well as the correct grounding and binding measures.

In a data center, if a copper cable link is connected from a ground panel in a grounded cabinet to a ground panel in another grounded cabinet, the open-circuit shielding layer may still pass the wire diagram test. This is because the connectivity of the shielding layer has historically been a DC measurement, and the DC signal will reach the remote unit through the public building ground rather than through the wiring link. Therefore, it is difficult to diagnose a cable fault with an open shield.

Fortunately, Fluke Networks already has the technology to solve this problem. Only the DSX-5000 CableAnalyzer™ provides the shielding integrity test function. It uses a patented AC measurement technology to prevent the grounded cabinet of the data center from causing the unconnected shielding layer to show that the connection is normal.

You are one step ahead of 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 Networks is the leader of this project and the editor of the standard, which stipulates field test methods and 2G accuracy.

In addition, you have plenty of time to deal with detailed content about Cat 8. There are currently no Cat 8 components shipped, nor any 25GBASE-T/40GBASE-T equipment available. At the same time, Fluke Networks is working closely with leading cabling manufacturers to ensure that you can easily and reliably test their solutions on site when you start the installation.