Talk:Gigabit Ethernet/Archive 1

message: 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)
thread_title:  Macs 

message: 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)
replies: text: 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)
thread_title:  1000BASE-T 

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

message: 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)
thread_title:  1000BaseCX 

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

message: 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)
replies: text: 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)
replies: text:  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)
thread_title:  does anyone actually make gigabit hubs? 

message: 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)
thread_title:  Forcing Gigabit 

message: 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)
replies: text: 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)

text: 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)
replies: text: 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)

text: 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)
thread_title:  What radio frequency is used on the wire? 

message: 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)
replies: text: 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)
replies: text:  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)
replies: text:  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)
thread_title:  1000BASE-SX distance 

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

text: 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)
thread_title:  Connectors 

message: 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)
replies: text: 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)

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

message: 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)
replies: text: 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)
thread_title:  Bias 

message: 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)
replies: text: 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)
thread_title:  Link to "Echo Cancellation" under 1000 Base-T leads to page that is not relevant to the sort of "Echo Cancellation" used 

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

message: 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)
thread_title:  Mentioning Apple? 

message: 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)
thread_title:  Misprediction in cablinginstall.com reference 

message: 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)
thread_title:  1000Base-LX MMF Conditioning cable.