As a bit of background, around 2002 there were some articles predicting the success of then newly announced 1000BASE-TX (TIA‐854), as inevitably enjoying much more commercial success than 1000BASE-T (IEEE 802.3ab). These predictions were partly based on betting that history was going to repeat itself, since 100BASE-T4 didn't see much adoption relative to the much more successful 100BASE-TX. The former used four Cat3 twisted pairs, whereas the latter used only two pairs of a Cat5 cable, thus reducing the number of transmitter and receivers needed. (The latter also supported full duplex so it had another advantage/bonus.)

But today hardly anyone remembers 1000BASE-TX, which still used all four pairs, but only uses a given wire unidirectionally, so theoretically cuts in half the number of transmitters and receivers relative to 1000BASE-T. (Full duplex operation remains the same as far the user is concerned, unlike in the 100BASE-T4 vs 100BASE-TX case.) 1000BASE-TX requires Cat 6 cable though, whereas 1000BASE-T needed Cat5e.

I can't find any evidence of actual products that supported 1000BASE-TX, though. So, did any such commercial products even exist or was this 1000BASE-TX entirely a "paper launch"? According to this page some products existed, but no concrete example is given. Which companies backed 1000BASE-TX back then? And what did they release in marketplace?

  • You must realize that ANSI/TIA/EIA-854 is a cable standard, not an ethernet standard like IEEE 802.3ab. ANSI/TIA/EIA never released any ethernet standard.
    – Ron Maupin
    Dec 2, 2015 at 0:03
  • @RonMaupin: According to those sources I've cited TIA-854 is titled "A Full Duplex Ethernet Specification for 1000Mbit/s (1000BASE-TX) Operating Over Category 6 Balanced Twisted-Pair Cabling". That doesn't sound like a cable standard to me. Dec 2, 2015 at 0:12
  • I've managed to find what is at least a draft of that TIA-854. Dec 2, 2015 at 0:27
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    As far as 1000BASE-TX goes, this is what cable vendors like Siemon say about it, "Note: 1000BASE-TX is an example of category 6 technology and not commercially available."
    – Ron Maupin
    Dec 2, 2015 at 0:58
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    I suspect[ed] something like that... an abortive attempt of TIA to enter the PHY specification business. Probably IEEE didn't want to hear of another 1000BASE copper standard... But usually a PHY standard like that has some vendors backing it. I can't seem to find any in this case. Of course Cat 6[a] is actually used in 10GBASE-T for which products certainly exist; Cisco etc. So it's not the absence of Cat 6 that doomed this 1000BASE-TX. Dec 2, 2015 at 1:03

2 Answers 2


It wasn't a "paper launch". Some vendors adopted both standards, for example Cabletron (Now Siemens) and Nortel (now dissapeared) offered at that time network cards for their modular switches with 1000 BASE TX interfaces. (Nortel Baystack 380 and SSR-GTX32-04 for example).

The main problem for this standard was that was cheaper and easier to change network cards than changing the cabling of a building or campus.

  • Is that really so? Sometimes 1000BASE-T gets misprinted (ahem even in reference material like the O'Reilly Ethernet: The Definitive Guide 2nd ed.) or combined written as 10/100/1000BASE-TX. The datasheet of the Nortel device lists the protocols in detail but I don't see TR-854 listed. As for the ebay listing, puhleeze anything goes on ebay in terms of "specifications". Doesn't mention TR-854 either. I can't find any serious specs for the latter, just a shoddy web page enterasys-networks.com/Enterasys_SSR-GTX32-04_1.html even from its [defunct?] manufacturer. Dec 2, 2015 at 14:24
  • As convincing evidence I'd like to see a datasheet for PHY chip made by some chip manufacturer claiming to explicitly support this TIA-854. Otherwise it's probably some kind of misprint. Note that the TIA-854 (if you read the standard) proposed to use TBI (same as GigE over fiber) not GMII interface (as 1000BASE-T) to the higher layers. So if a copper PHY doesn't claim support for TBI, it's already a clear indication it's not actually a TR-854 one. There are some obscure Taiwanese ICs that list "1000BASE-TX" but GMII as interface... again misprints. Dec 2, 2015 at 14:32
  • s/TR-854/TIA-854 above. Dec 2, 2015 at 14:33
  • router-agent.de/catalog/enterasys%20networks/ssr-gtx32-04.html which has more details than the "manufacturer" these days, lists 4 x 1000BASE-T (not TX as the ports for that SSR-GTX32-04 device. Dec 2, 2015 at 14:42
  • And found an actual datasheet with "IEEE 802.3ab 1000Base-T Characteristics". Some marketing blockhead (at the defunct Enterasys) probably called it TX. Dec 2, 2015 at 14:47

1000BASE-TX has not gained wide recognition, largely due to the expense of Cat 6 and 7 cable requirements and the rising cost of 1000BASE-T products.

I constantly wrestle with this question.

Some vendors(Fiberstore) erroneously call 1000base-t SFP a 1000base-tx SFPs.

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