How to use it?
The American commitee for copper cable networks TIA TR-42.7 approved the specifications for Category 8 cabling (TIA 568C.2-1). This is the latest standard, designed to support future applications with speeds of 25Gb/s and 40 Gb/s. The standards for these speeds, IEEE 25GBASE-T and IEEE 40GBASE-T, are yet to be adopted.
After all this waiting, you're probably wondering how Category 8 will affect cable installations and their testing.
For data centers only
The new standard only describes links with length of up to 30m, with a maximum of 2 sockets and a bandwidth of up to 2GHz. For this reason, you are unlikely to use it in local area networks - LANs. It is specifically designed for high-speed applications in data centers, where in the future 25Gb/s and 40 Gb/s will be used for server-switch connections.
Although SFP+ and QSFP+ cables can also support these speeds, they have a relatively small distance limit of 5 to 7m. With the 30m distance it offers, Category 8 is much more flexible for cases where the main switches are placed at the “end of the row” or in the “middle of the row” and are compatible with existing Ethernet technologies.
Alien Crosstalk – remains
As we know from Cat.6A, the requirement for shielding of the cable network is important. With Cat.8, the influence between adjacent cables (alien crosstalk) is an even greater concern. Here the signals are four times higher in frequency than Cat.6 (4x500MHz). And despite a well-shielded structured cabling system, the Alien Crosstalk parameter (as well as all other parameters) must be tested and ensured to be within the standard.
Shielding continuity is mandatory
If you haven't done shielded cabling systems, you should learn how now. With Cat.8 everything is well shielded and well grounded here! It is very important that the shielding does not break anywhere – from one shielded and grounded patch panel in a grounded cabinet to another shielded and grounded patch panel in another grounded cabinet. Breaking the shielding will result in a test failure.
You have time
The specifications for Cat.8 are clear, but the IEEE 25GBASE-T and IEEE 40GBASE-T standards are still pending. Major test equipment manufacturers are not yet ready with the tools to provide easy and fast verification of built Cat.8 networks. Components for Category 8 structured cabling systems are still rare.
/by Mark Mullins – Fluke Networks/
