I'm looking to buy a Cat 8 patch cable. I found a cable that I like that meets ISO/IEC 11801 Class I and Class II but it is not compliant to TIA Cat8 (As defined in ANSI/TIA-568.2-D) which has slightly different requirements.

Cable that I'm looking at: https://www.leviton.com/en/docs/Leviton_SFS8D-5LS_Atlas-X1_Cat_8_SFTP_Cable.pdf

I live in the United States, and was wondering if there are drawbacks for patch cables that don't meet the TIA requirements.

I did some research already, and according to this website it basically shows more check boxes for the ISO standard.

And this website shows that TIA cables are 150 Ω and ISO 11801 cables are 100 Ω.

So far that's the only difference I could find, but I'm not even sure how that effects the patch cable. Does the Ohms rating effect patch cables? Are devices in United States only compatible with 150 Ohms cables? Are there any drawback to using the TIA patch cable in the US Region?



Ohms Whats the difference

  • My question is why do you want that? You cannot mix it with other cable categories, it is limited to three meters, and it is for 25GBase-T and 40GBase-T, adding nothing for anything less than those. You really only need it if you have that for your horizontal cabling.
    – Ron Maupin
    Jan 13, 2020 at 22:30
  • 1
    ISO doesn't use the "category" naming system. If they're calling it Cat-anything, then it's ANSI/TIA. ISO is "Class [letter]". If you want to know the differences, compare the fine print of each standard. The last image above shows the key difference: 150ohm vs. 100ohm. (mixing impedance is a problem) You should probably consult a cabling professional. Anything faster than 10Gb, I wouldn't attempt with copper.
    – Ricky
    Jan 14, 2020 at 2:44
  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can post and accept your own answer.
    – Ron Maupin
    Dec 17, 2020 at 14:53

1 Answer 1


Either category 8.1 (class I) or category 8.2 (class II) is compatible with 40GBASE-T or 25GBASE-T - but they cannot be mixed.

Cat 8.1 is designed to interoperate with Cat 6A (U/FTP or F/UTP, US style) using 8P8C connectors, while Cat 8.2 interoperates with Cat 7 (S/FTP or F/FTP, international style) using TERA or GG45 connectors. You need to choose which one fits your existing network and harmonizes with local standards.

Does the Ohms rating effect patch cables?

Yes. Both the connectors and the different cables cannot be mixed - an impedance change causes reflections and severly reduces reach. You need to pick patch cables so that only one standard is used on each run.

Are there any drawback to using the TIA patch cable in the US Region?

Can't really say what the legal regulations are in the US, but your company might have (should have) a strict policy which standards to adhere to in order to avoid building incompatible structures.

If you need to pull cable you should seriously consider fiber (preferrably single-mode for runs of 50+ m) as it can still grow considerably while Cat 8 is maxed out at 40 Gbit/s.

  • This doesn't answer what's the difference between the standards, especially between Cat 8 and Cat 8.1. And my questions about the Ohms. Jan 13, 2020 at 21:57

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