Talk:Gigabit Ethernet/Archive 1

Archive 1

Macs

Um, not sure why the G5 was singled out as having GbE standard. Power Macs have been shipping standard with GbE since mid-2000, and PowerBooks have had it standard since late 2001.

Sources: Here and here.

--anonymous, Mac-loving Wikipedia newbie, 21 Sep 2004

I don't keep up with Mac's all that much, but that I recall, it was the first mainstream computer that came equipped with GbE.

I'm not sure i'd call a powermac mainstream, imo its more of a high end workstation. Plugwash 22:07, 7 June 2006 (UTC)

Abbreviation

What is the 'proper' abbreviation for Gigabit Ethernet? "GbE", "GE" or something else?

Fourohfour 13:00, 29 November 2005 (UTC)

I don't believe there is a 'proper' abbreivation. When there is no doubt as to the meaning, I suppose GE could be used, but there would be almost no chance for confusion if GbE were used. Mrand 02:33, 15 March 2006 (UTC)

Emileaben 18:53, 12 April 2006 (UTC)

How about the abbreviation GigE ('gige','gigE')? I hear/see that more often then GbE or GE, I guess it's because it's easy to pronounce.

Speed

What sort of transfer speed is it actually capable of?

I get about 35 MBytes/sec for file transfers.--Dwedit 13:19, 25 January 2006 (UTC)

Transfer speed between what? On general purpose computers, you often can't achieve nearly the rates that you can on dedicated communications equipment (switches and routers), where full line rate is achievable. Mrand 02:33, 15 March 2006 (UTC)

What I would like to know is what the theoretical speed is. Is it a gigabit or a gibibit? And on what layer does it transport that ammount of data? That is, are the ethernet header, CRC and preamble (and anything I forgot) included in the 1 gigabit, or can you send 1 gigabit/s on top of them? So what is the theoretical maximum bytes/s and (1500 byte)packets/s over raw ethernet (so not even using IP) that could be send then? This unsigned comment was made by 213.224.83.20 02:10, 5 June 2006 (UTC)

It actually is a gigabit, not a gibibit. Network communications almost always use "kilo" to mean 10^3, not 2^10, and so on. 1 Gbps is the bandwidth of the physical layer, which is to say it does not include the preamble, sfd, header, or checksum. The preamble is 7 bytes, the sfd 1, the source and destination addresses 6 bytes each, the type is 2 bytes, and the checksum is 4, for a total overhead of 26 bytes per frame. And the payload is at most 1500 bytes. So, theoretically, at 100% utilization you could get just shy of 983 Mbps in payload at the MAC layer. Of course, realistically, a typical LAN won't get anywhere near 100% utilization. And you might send smaller packets that have to be padded (on half-duplex links). And you've got an LLC header, which is another 3 bytes, then IP uses at least 20 bytes, and TCP is at least another 20 bytes. And some frames/packets/messages might have to be retransmitted. So you'll end up with a lot less.--Babomb 06:33, 28 June 2006 (UTC)

Does anyone actually use half duplex gigabit ethernet? i've never seen anywhere selling a gigabit hub (even though the standard technically allows them) and i can't think of any other reason to use it. Plugwash 12:13, 28 June 2006 (UTC)

BTW as the first two posts kind of hint gigabit ethernet is rarely the bottleneck unless you are using very high end kit for the rest of the system. A file transfer is likely to hit the PCI bus TWICE (once on its way from the hard drive to the main memory and again on the way back out to the ethernet adaptor) and normal PCI has an absoloute maximum bandwidth of arround 1 gigabit per second. A motherboard with high end ethenet and SCSI controllers on PCI-X or PCIe and a good stack of software on top is likely to be a very different matter. Plugwash

1000BASE-T

The author wrote: "The symbol rate is identical to that of 100BASE-TX (125 MBd)". I don't think it is identical: 100BASE-TX is 12.5 MBaud, and GbE (both 1000BASE-X and 1000BASE-T is 125 MBaud) --131.211.40.2 16:19, 9 August 2006 (UTC)

Perhaps you confused Byte and Baud? 100BASE-TX is 12.5 MByte/sec, but is 125 MBaud. It is 125 MBaud because one symbol is sent every second (where each symbol represents 1 bit). 1000BASE-T gets away with the same symbol rate because each symbol represents 2 bits and it sends four symbols at the same time (2 bits per symbol * 4 twisted pair * 125 Msymbols/sec = 1 Gbps). Hope that helps. Mrand 02:18, 10 August 2006 (UTC)

In the symbol/voltage table (1oooBASE-T details) I see the same voltage for different symbols. (e.g. +1 is 001, 101) What am I missing? Should there be a bit of clarification in the section, or am I too easily confused?John N. 17:15, 12 March 2007 (UTC)

1000BASE-TX

Shouldn't 1000BASE-TX be mentioned as an implementation og Gigabit Ethernet? After all it's possibly the most common implementation.

Dantams 17:40, 4 March 2006 (UTC)

It was mentioned until a large rewrite by Tas50. Do you know of a reference that sets the record straight?matt kane's brain 15:12, 8 March 2006 (UTC)

There should definitely be mention of 1000Base-T (I assume that is what you were referring to), which was not included in the original GbE spec. It was introduced later. I added a brief mention. In reality, all the 1000Base- articles could almost certainly be combined into one. The -LX, -SX, -CX, and -T articles are all very brief and wouldn't need much more fleshing out to explain them in acceptable detail. Mrand 02:33, 15 March 2006 (UTC)

I think he means 1000BASE-TX, a gigE implementation that is considered failed. Xnolanx 16:36, 7 June 2006 (UTC)

Hmmm. 1000Base-TX is considered failed, yet he called it the most common implementation. So, was he referring to -TX or -T? I think this may prove the point that people confuse the two. I've pulled the straggling 1000Base-TX article into this one. Mrand 19:12, 7 June 2006 (UTC)

Thanks, that should clear it up a little bit.

Reorganizing

I've reordered a number of the paragraphs so that they hopefully flow better. If the consensus is that I've made it worse than it was, we can revert it. Long term, I think all the 1000Base- articles should be folded back into this page. There is no reason to have one or two paragraph long articles on each one of sub-optics. Any comments? Mrand 20:52, 5 June 2006 (UTC)

Not even long term: Just go ahead and merge them in now. KelleyCook 20:59, 5 June 2006 (UTC)

I'm done with the merging. Everyone please feel free to edit away and make it the article it should be. Mrand 22:25, 5 June 2006 (UTC)

1000BaseCX

Would it be appropriate to create a separate article for 1000BaseCX to redirect to this page? I was searching for info on this standard and was a bit taken back that there was no article for it here. Eventually I made my way to this page, but a redirect would have been more efficient. Also, is there any more info on 1000BaseCX that could be included or would it just be useless pedagoguery?

Done. Guy Harris 00:12, 20 July 2006 (UTC)

Line Codes

This article says 1000BASE-T expands 8 bits into four 3 bit symbols, while the 8B10B article explains how the same 1000BASE-T expands 8 bits into a single 10 bit symbol. How do they fit together? Also both articles should have links to each other. CannibalSmith 07:25, 1 June 2007 (UTC)

Edit: 8B10B says Gigabit Ethernet, not 1000BASE-T specifically. So is 8B10B for optics only? CannibalSmith 07:29, 1 June 2007 (UTC)

Correct. I added a few words next to the link on the 8b/10b page - feel free to add more here or there if you think it could be made more clear! Mrand ^T-C 13:10, 1 June 2007 (UTC)

What is actual data thoughput?

Does the Giga actually move exactly 1000Mb/s, and how much of that data is reserved for error correction and packet addressing (overhead)?

Word is some 20% is for overhead. --Flightsoffancy (talk) 15:50, 28 January 2008 (UTC)

1. There is no error correction built into GigE itself. Other software or hardware layers would have to perform that function if it is desired.
2. The packet addressing/overhead (by which I assume you mean things like MAC address, pkt type, CRC checking (which is error detection), is the same for all variants of Ethernet. See Ethernet#Physical_layer for details.
3. There is 25% overhead for the line coding added to the packet addressing/overhead, as discussed in the article. Are you saying that you don't find that section of the article clear?

—Mrand ^T-C 17:14, 28 January 2008 (UTC)

I just tested my network with

dd if=ubuntu-8.04.1-dvd-amd64.iso iflag=direct bs=1M count=10 > /dev/null

10+0 records in

10+0 records out

10485760 bytes (10 MB) copied, 0.111175 s, 94.3 MB/s

BTW, 94.3 MB/s = 754 Mb/s which is not quite a gigabit. So I'm guessing the rest is just lost to overhead.

Gigabit ethernet has a signalling rate of 1,250,000,000 bit/s. Through the use of 8b/10b encoding, translates into a data rate of 1,000,000,000 bit/s. Ethernet headers do require some of the 1 gigabit to be used as controlling data, and lower the throughput of the actual payload. TCP/IP headers will further lower the payload.

Example of typical 1500 byte ethernet frames, IPv4, and TCP:

• Datarate: 1,000,000,000 bit/s
• Ethernet overhead: 1526 total, 1500 bytes payload = 982,961,992 bit/s
• IP overhead: 1500 bytes total, 1484 bytes payload = 972,477,064 bit/s
• TCP overhead: 1484 bytes total, 1468 bytes payload = 961,992,136 bit/s

This puts your theoretical max throughput at 96.2% of 1 Gbit/s, 114 MiB/s. I would guess that 90% usage, or 107 MiB/s would be achievable throughput with sufficient hardware at either end of the link. —fudoreaper (talk) 02:33, 19 January 2009 (UTC)

does anyone actually make gigabit hubs?

they are certainly allowed by the spec (there is a specific section on repeaters which talks about joinging 2 or more segments) but does anyone actually make them? Plugwash 12:05, 26 March 2007 (UTC)

Are you sure they're allowed by the spec? I don't have a copy to check, but I was under the impression that 1000BaseT was the first 802.3 standard to /require/ full-duplex on all links. At least some of my NICs don't advertise 1000BaseT/half. As far as I've heard, any gear that supports this is extending the specification. I could very well be wrong, of course. Do you have a reference?--ktims (talk) 18:00, 27 April 2008 (UTC)

You can get a slighly outdated version of the spec free from http://standards.ieee.org/getieee802/download/802.3-2008_section3.pdf . Repeaters are clearly mentioned though I note the following has now appeared "NOTE—This repeater is not recommended for new installations. Since May 2007, maintenance changes are no longer being considered for this clause.". Plugwash (talk) 21:02, 28 August 2009 (UTC)

Forcing Gigabit

The article says that several implementations allow the user to force gigabit operation to eliminate autonegotiation issues. I belive this is misleading. Autonegotiation is *required* for gigabit transcievers because it sets parameters other than just speed and duplex. These implementations that purport to allow 'forcing' operation really only eliminate non-gigabit modes from the candidates offered by the negotiation mechanism. Autonegotiaion still happens, it just won't allow modes other than gigabit to be negotiated. Added by 192.223.243.6 on 13:44, 27 April 2007.

I know many Broadcom chips that can (at your risk and out of the standard) disable negotiation, force speed to Gigabit, force Duplex, and force Clock source to local Master or Slave--Efa2 (talk) 12:54, 27 July 2009 (UTC)

CAT-5 with 1000base-T ?

The 802.3ab standard 'require' CAT-5E. CAT-5 is not allowed. While may work, and many web site mistakely report as OK, it is not ufficially supported by IEEE. —Preceding unsigned comment added by Efa2 (talk • contribs) 12:58, 27 July 2009 (UTC)

You acknowledge that there's some disagreement around this. Can you please provide a citation to the section of the 802 standard that requires CAT5E? You've not provided one here and you've not included one with your recent edits. --Kvng (talk) 18:00, 27 July 2009 (UTC)

I disagree with Efa2. From the IEEE 802.3 standard, Section 3, Page 151: "The 1000BASE-T PHY employs full duplex baseband transmission over four pairs of Category 5 balanced cabling." It very clearly states that 1000Base-T opperates over Cat5 cabling, no mention of Cat 5e. Unfortunately we cannot link directly to the source document, but you can download it for free from the IEEE website. I will further point out that 802.3ab was ratified in 1999, and Cat 5e was defined in 2001 as a standard that supersedes and deprecates Cat 5. —fudoreaper (talk) 23:02, 28 July 2009 (UTC)

That is my basic understanding also. Mine actually goes a little further. 1000BASE-T uses the same 125 MHz carrier and employs more advanced signal processing and so is actually more tolerant of cable imperfections than 100BASE-TX. I'll revert Efa2's changes --Kvng (talk) 16:20, 29 July 2009 (UTC)

Yes you can use cat5 for gigabit but it is recommended to use cat5e because of it higher frequncey i am not getting involved in this debate just stating information--Andrewcrawford (talk - contrib) 19:54, 26 August 2009 (UTC)

We don't need to debate but it would be helpful if you could cite a source for your information. Cat 5e does not have a higher frequency rating than Cat 5 (you might be thinking of Cat 6 or Cat 7), it merely has a crosstalk requirement that is missing from the Cat 5 specification. The primary reason to use Cat 5e (for new installations) is because the Cat 5 standard has been deprecated. My concern in all of this is we don't want someone with an existing Cat 5 cable plant getting the impression that they need to upgrade to Cat 5e in order to use 1000BASE-T in that plant --Kvng (talk) 01:17, 4 August 2009 (UTC)

I will need to dig my university notes out to fidn the soruce for it, yes it doe has crosstalk reduction but it also has a slightly higher frequncy than cat5, to fully use gigabat you really need cat5e but it can work jsut as well in cat5 sometimes just missing full speeds but it suffer mostly from errors which is wher ethe crosstalk comes in. so in thoery people should be upgraidng but if i was advicing it would be upgrade to cat6 perfer cat7--Andrewcrawford (talk - contrib) 19:54, 26 August 2009 (UTC)

Do you disagree with my source from the IEEE that states 1000BASE-T operates over Category 5 cabling? Sure Cat5e is superior, but the standard states it operates over Cat5. You state: "to fully use gigabat you really need cat5e". I don't understand why you think that. The 802.3 standard states Cat5 is the required cabling, and does not state a requirement for Cat5e. —fudoreaper (talk) 11:01, 30 August 2009 (UTC)

Well by the same standard it operates over cat3 but just because it operates over a cable does nto mean that it workign ot it fullest capiacty and having little errors. Workign on cat5 it will archive maximum speeds ocassionally it more likely ot achive 60-70% speed of gigabit and with at least 30% errors, due to crosstalk and ot the fact cat5 is a slightly lower frequncy. the standard was made before cat5e was developed, so if cat5e isnt the required cabling hwy develop it?--Andrewcrawford (talk - contrib) 11:08, 30 August 2009 (UTC)

The original standard 802.3ab ratified in 1999 speak about Cat5 because Cat5e doesn't exist

The current standard 802.3-2008 speak about Cat5e or Cat5 plus "additional performance parameters specified in ANSI/EIA/TIA-568-B1 Annex D." If you see what say -B1, it only recognizes Category 5e (or higher category) cabling. So pure Cat5 is not supported for 1000BaseT.--Efa (talk) 15:05, 26 August 2009 (UTC)

Efa appears to be correct. Here's what I find in 802.3-2008 Annex 40A: "Whether installing a new Category 5/Class D balanced cabling system or reusing one that is already installed, it is highly recommended that the cabling system be measured/certified before connecting 1000BASE-T equipment following the guidelines in ANSI/EIA/TIA 568-B1 Annex D."

Although this appears in the 1000BASE-T section of the specification, I suspect this advice also applies to 100BASE-T. The primary issue that everyone has had to work around is that the original Cat 5 specification omitted some critical cross-talk performance parameters. The "Cat 5" marking does not guarantee adequate performance. --Kvng (talk) 19:49, 26 August 2009 (UTC)

But the original 1000BaseT standard--IEEE 802.3--states that will operate over Cat5 cabling, right? If it works over Cat5, by specification, then Cat5e is preferred, but no required. —fudoreaper (talk) 11:01, 30 August 2009 (UTC)

I believe my previous comment agreeing with Efa was too broad. To be clear, I did not find anything normative 802.3-2005 or 802.3-2008 that requires enhanced Cat 5 (Cat 5e) what I found was informative - the recommendation I quoted above. What FedorReaper is saying is what the article currently says and I think the article is correct. --Kvng (talk) 16:24, 30 August 2009 (UTC)

While the pair carrier is 125MHz both on 100baseTX and 1000baseT, the first use only two pair one dedicated to TX and the other dedicated to RX on 3 voltage level only, the 1000baseT standard use all four pair, simultaneously in TX and RX, on 5 voltage level, much more complicate to decode. Gigabit need 4 DSP core integrated per GigaPhy to delete own transmitted symbols, near and far crosstalk from other pairs, and recover wanted received informations on each pair. This is because is so important to have a low crosstalk cable.--Efa (talk) 22:47, 26 August 2009 (UTC)

My edit of 2008 September 11 was on the same line, but it was removed in the time: [1]--Efa (talk) 07:45, 28 August 2009 (UTC)

It looks to me like you skipped a step jumping from where you establish that gigabit Ethernet is more complicated to where you assert that it has more stringent crosstalk requirements. My understanding is that the same fancy DSP used to cancel own transmissions is used to cancel crosstalk more effectively thus 1000BASE-T is able to tolerate more crosstalk in the cable than 100BASE-TX which was developed when PHYs were analog and DSP on 125 MHz signals was not feasible. I come by this understanding through conversations with PHY designers. I don't have a reference so I've kept this information out of the article. --Kvng (talk) 15:45, 28 August 2009 (UTC)

What radio frequency is used on the wire?

1000BASE-T uses radio frequency on the copper, what is the frequency range? What about for 100BASE-T? this information does not seem to be documented anywhere on wikipedia (that I could find) —milliamp —Preceding undated comment added 12:43, 10 October 2009 (UTC).

Both 1000BASE-T and 100BASE-TX use a 125 MHz "carrier". 1000BASE-T uses more wires and more efficient encoding to get the additional throughput in the same bandwidth. —Preceding unsigned comment added by Kvng (talk • contribs) 20:20, 12 October 2009 (UTC)

I am confused by your answer, is 125 MHz the frequency or the bandwidth? If it is the bandwidth, in what frequency range is it transmitted at? —milliamp —Preceding undated comment added 01:36, 18 October 2009 (UTC).

125Mhz is the symbol rate, it's a baseband system so the band would be roughly 0-62.5MHz (for the signal itself, harmonics will go higher, it doesn't actually get right down to zero due to the encoding applied before symbols are sent out)Plugwash (talk) 01:51, 18 October 2009 (UTC)

On a simpler system (e.g. 10BASE-T), 125 MHz is the "symbol rate" would be known as the "bit rate" but gigabit Ethernet uses 5 level coding so you get multiple bits per symbol period. Symbols are further organized into groups of 10. The group period gives you an approximate lower bound for bandwidth at 6.25 MHz. Information is therefore conveyed in a 6.25-62.5 MhZ frequency range. Cat5 cable is specified at 100 MHz to give margin for the harmonics. --Kvng (talk) 17:06, 19 October 2009 (UTC)

1000BASE-SX distance

Summary table indicates 500 m. The 1000BASE-SX section mentions 220 and 550 m. The text leads me to believe that 220 m is the only condoned distance. If that's the case, should the others even be mentioned? --Kvng (talk) 21:33, 4 February 2009 (UTC)

I think your eyes are maybe jumping sections? I only see 220 mentioned in the -SX section. In each of the sections, the various distances refer to the type of fiber used. Perhaps not written real well, but I think the text mostly reflects that. Or are you seeing something else? —Mrand ^{Talk • C} 23:51, 4 February 2009 (UTC)

Oops. The problem is with 1000BASE-SX not with 1000BASE-LX. I've corrected the title of this section. Do you see what I'm talking about now? --Kvng (talk) 17:21, 5 February 2009 (UTC)

I see that various distances are listed for different types of fiber. I believe the vendors (and possibly standards) endorse this. Do you believe that to not be the case (and if so, could you provide more information why)? Thanks! —Mrand ^{Talk • C} 18:56, 5 February 2009 (UTC)

The table still shows 500m and the text 220m. —Preceding unsigned comment added by 79.141.129.42 (talk) 19:42, 14 February 2009 (UTC)

I've visited the 802.3 standards documents and cleaned things up a bit. 1000BASE-SX distance specification is 220-550 meters depending on the type and quality of fiber used. I've retained claims of longer distance capabilities for now but marked these as requiring citations. --Kvng (talk) 01:17, 15 February 2009 (UTC)

I can't find anything on the cited page that claims longer distances possible, updated page 20.139.226.71 (talk) 05:31, 14 June 2012 (UTC)

Connectors

It would be very kind of those knowledgeable about this topic to describe the connectors (especially the fiber optic ones) like the Fast Ethernet article does. --Treekids (talk) 21:28, 30 October 2009 (UTC)

What's wrong with Optical fiber connector? ;-) --Zac67 (talk) 23:02, 30 October 2009 (UTC)

it very complicated.... —Preceding unsigned comment added by 122.55.184.210 (talk) 01:12, 22 April 2010 (UTC)

 Done Looks like we have the same level of discussion with respect to cabling and connectors here and on fast Ethernet. --Kvng (talk) 22:45, 17 November 2010 (UTC)

Gigabit Ethernet and POE

Can somebody who maintains this page add an FAQ section? I have a question about using POE on a Gigabit connection. My understanding was that 10baseT and 100baseT use only 2 pairs, and POE is used over unused wires. So if gigabit uses all four pairs, how does POE figure into the equation? If that is explained in a different part of Wikipedia, then a link would suffice.

Go ahead and delete this comment when appropriate.

Thanks. —Preceding unsigned comment added by 64.58.145.3 (talk) 23:07, 6 October 2010 (UTC)

The PoE article probably explains this better than I can but, PoE can be run in two modes, A and B. In mode A, the power is run on the same pairs as data. In mode B, it uses the spare pairs. As for gigabit connections, it does work but it is beyond me how it works. I think the PoE article touches on that too. Mateo2 (talk) 21:41, 17 November 2010 (UTC)

I've done a little work on PoE to try and clarify this. A phantom power technique is used to deliver power and data over the same wires. --Kvng (talk) 22:40, 17 November 2010 (UTC)

Now my turn to ask a gigabit PoE question. With no spare pairs on GE, is there no such thing as a GE midspan PoE injector? --Kvng (talk) 22:40, 17 November 2010 (UTC)

e.g. AXIS offers some multiport PoE injectors (midspan) that are GE capable. -- Zac67 (talk) 08:29, 19 November 2010 (UTC)

Bias

This article is written like an advertisement.

The result of research done at Xerox Corporation in the early 1970s, Ethernet has evolved into the most widely implemented physical and link layer protocol today.

"the most widely implemented..." does not have a source, and is rather obviously ad-like. I forgot how to ad the "written like an advertisement" tag to add, but if someone would fix this, them tell me, thanks!

Austinburk (talk) 17:08, 15 February 2011 (UTC)

You seem to be referring to the history section, which seems to present things in a reasonably neutral light... so I don't see a need for an avertisement tag. —Mrand ^{Talk • C} 15:24, 19 February 2011 (UTC)

Link to "Echo Cancellation" under 1000 Base-T leads to page that is not relevant to the sort of "Echo Cancellation" used

The Echo Cancellation article is entirely dedicated to echo cancellation in voice communication and ancient modems - that is, to ACOUSTIC echo cancellation. This is unrelated to gigabit ethernet. If we're linking to that article from here, it needs to describe Echo Cancellation in the context of data transmission, which I imagine would involve a very different approach (maybe it doesn't - but I don't know, because the Echo Cancellation article doesn't mention it!)

I'm putting this post under the Gigabit Ethernet article, not the Echo Cancellation article, because I suspect there may already be an article for echo cancellation in data transmission (under a different name).

76.24.24.230 (talk) 08:45, 16 July 2011 (UTC)

I have replaced the link and text to point to Adaptive equalizer. An (acoustic) echo canceller is an adaptive equalizer (plus other stuff) operating in the audio band. --Kvng (talk) 13:19, 19 July 2011 (UTC)

1000BASE-CX Nearly Obsolete

"The IEEE 802.3z standard includes 1000BASE-SX for transmission over multi-mode fiber, 1000BASE-LX for transmission over single-mode fiber, and the nearly obsolete 1000BASE-CX for transmission over balanced copper cabling." --what makes 1000BASE-CX nearly obsolete? Is this an opinion? Is this related to the percentage of systems deployed? Can it be referenced to something? — Preceding unsigned comment added by JJohnston2 (talk • contribs) 19:44, 10 July 2012 (UTC)

Sorry I don't have sources to hand but here is my perception of the situation.

1000BASE-T has become by far the dominant physical layer for short to moderate length runs of gigabit ethernet. To the extent that most computers sold come with one or more 1000BASE-T ports and if you say gigabit ethernet without mentioning the physical layer everyone will assume you mean 1000BASE-T. The fiber standards are far less common than 1000BASE-T but they remain relavent because there is a real need to link switches that are more than 100M apart.

I think 1000BASE-CX4 may have slightly lower latency than 1000BASE-T but I'm pretty sure the niche who care about minimising latency at all costs have moved on to 10 gigabit ethernet with SFP+ direct attach.

-- Plugwash (talk) 16:29, 10 January 2013 (UTC)

Notes

The notes section includes a link to a page that has gone: http://www.cisco.com/en/US/products/ps10018/index.html. AndrewRH (talk) 13:58, 23 January 2013 (UTC)

Not convinced it was worth salvaging, but I fixed it with an archive link. -—Kvng 00:35, 24 January 2013 (UTC)

Mentioning Apple?

How exactly is mentioning that Apple allegedly first put a 1000BASE-T port into a PC relevant in article about Gigabit-Ethernet technology? As far as I can tell, Apple had nothing to do with developing the actual standard, the technology or the core parts of the NIC electronics in G4 Powerbooks. And obviously network devices (at least Cisco) and server computers (at least IBM) sported 1000BASE-T before Apple's laptop did.

That's a bit like mentioning that the first car to sport a built-in FM radio was brand X, in an article about FM radio, without mentioning either the producer of that car radio set or who built the first fm radio at all.

Anyway, looks like some kind of stealth advertising to me. — Preceding unsigned comment added by 92.206.177.223 (talk) 22:10, 21 February 2013 (UTC)

Misprediction in cablinginstall.com reference

A recently added reference at the end of the 1000BASE-TX section dates from 2002 and incorrectly predicted 1000BASE-TX would become the more popular and cheaper option, which is the opposite of the claim in the article: "However, this solution has been a commercial failure, likely due to the required Category 6 cabling and the rapidly falling cost of 1000BASE-T products". This reference may still be useful as a source for wire pair usage and as a source for the "in theory" claim in the previous sentence: "The simplified design would have, in theory, reduced the cost of the required electronics by only using four unidirectional pairs (two pairs TX and two pairs RX) instead of four bidirectional pairs." So maybe the reference just needs to be moved back a sentence, and an additional source found (if needed) for the fact that 1000BASE-TX ended up "losing" to 1000BASE-T. — ChrstphrChvz (talk • contribs) 07:29, 6 November 2018 (UTC)

1000Base-LX MMF Conditioning cable.

The article suggests that 1000Base-LX can be used to 300m without a conditioning cable. Is this correct? The IEEE 802.3 clause 38.4.1 says the conditioning cable is required for MMF and the source provided suggests the same. — Preceding unsigned comment added by Nateelmore (talk • contribs) 15:13, 3 July 2019 (UTC)