Talk:Medium-dependent interface

merge already.... its 2010 now —Preceding unsigned comment added by 202.180.65.233 (talk) 23:49, 12 May 2010 (UTC)

yes, obviously merge.--Boscobiscotti 07:05, 16 May 2007 (UTC)

Merge. BTW I think that MDIX's on computers are no longer "rare." trebor 02:48, 28 July 2007 (UTC)


 * Is that personal observation or some actual data? My guess is that most are Auto-MDIX now days. Hardly worth the support calls since it is included on all modern PHY chips. W Nowicki (talk) 19:23, 28 June 2011 (UTC)

Merging MDIX with this article.
Due to the previous comment regarding merging, and 4 month inactivity otherwise I have decided I will merge the articles (I am stating this for the purpose of tracking changes, not as an authority; though I can't see anyone wanting this to be split in the near future). Tyler 18:45, 8 August 2007 (UTC)

After the merge
Please note that the page Talk:MDIX contains some information that is now relevant here, but I did not want to move peoples' comments.

I merged the articles and cut some redundant information, but the article could use some editing to improve it. I lack the artistic vision to pull it off, but if someone is interested I think it could look better. Tyler 19:05, 8 August 2007 (UTC)


 * Alas, it still reads like three articles tacked together. I think what it really needs is a diagram to explain the cross-over business, instead of repetition. W Nowicki (talk) 23:56, 10 June 2011 (UTC)

Auto-MDIX merge
Merge banners were up for 6 months with no discussion so I took the liberty of merging Auto-MDIX into this article. --Kvng (talk) 21:09, 17 August 2010 (UTC)

Uncited anecdote

 * Auto-MDIX was spawned one day when Melvin was frustrated while looking for a cross-over cable in the lab, and asked Dove to invent a solution. His inspiration led Dan to develop the method which utilizes a pseudo-random number generator to decide whether or not a network port will attach its transmitter, or its receiver to each of the twisted pairs used to Auto-Negotiate the link.

Will try to gather sources and add more encyclopedic language. W Nowicki (talk) 18:28, 17 June 2011 (UTC)

Question
This is being moved from my talk page because it was by a non-registered user:
 * I could not understand if auto mdix works only if the two devices have support for it, or if it works whenever one of the devices supports it.


 * If you could answer this, I'd be more than glad to fix the page. Thanks — Preceding unsigned comment added by 189.33.50.202 (talk) 06:38, 18 June 2011 (UTC)

I tried to fix, but still needs work, as does the section in Ethernet over twisted pair which is somehat redundant, as well as Ethernet crossover cable of course. From my reading of the sources, as long as at least one end does Auto-MDIX it should work. In fact, with only one end it would be simpler: just try one way and if it does not work try the other. The desire to handle two back-to-back is what prompted the pseudo-random number part. That might explain why it seems to have been picked up fairly quickly on host interfaces, but a bit slower on switches. Will try again. W Nowicki (talk) 20:14, 18 June 2011 (UTC)

poor article name
This article is about the wiring of one particular family of medium dependent interfaces not about medium dependent interfaces in general (of which ethernet alone defines many). Further when talking about the wiring conventions the abbreviations are nearly always used. I propose a rename to "MDI and MDI-X" or "twisted pair medium dependent interface". Any thoughts from others before I do this? Plugwash (talk) 16:53, 29 August 2011 (UTC)


 * Very good point, right now it describes the MDI for twisted pair Ethernet, not the term in general. I would say hold off a little until we reach a consensus, since there has been some brownian motion with this area of articles. This article itself has been improved and not as bad as many others that need more work in my (biased) opinion. I am generally not a fan of acronyms in article titles, even though technical documents do use them more often than spelling out the name at first use, which is what I prefer. Two solutions I would support: 1) evolve this article into a general description of medium dependent interfaces, by widening the lead a bit, and adding a section that enumerates at least the others for Ethernet family (the pluggable transceivers? which have gone through a merge of their own) and others, if any (ATM, SDH, Fibre Channel perhaps?) briefly pointing to their articles. 2) just merge as a section into Ethernet over twisted pair. Perhaps some combination of the two would make the most sense. Ethernet over twisted pair is mostly about cabling anyway so far. MDI is a disambig page that redirect here for now, but perhaps this could just be the small article about the concept in general and the BASE-T details moved to be with the other BASE-T details? Somewhere it needs to mentioned that optical interfaces generally do not have the MDI-X concept; they are usually the same orientation and assume the cross-over is done in the cable. W Nowicki (talk) 17:42, 29 August 2011 (UTC)
 * I think the best bet is to make this article about medium dependent interfaces in general and move some of the twisted pair specific stuff over to ethernet over twisted pair. I've made a start


 * BTW on the subject of fiber interfaces my understanding is that duplex fiber cables and couplers are always crossed. So there is no need for special crossover cables. Can anyone confirm this? 86.22.248.209 (talk) 19:21, 29 September 2011 (UTC)
 * All SC or LC cables I've seen can be used either crossed or uncrossed. ST cables/ends are connected independently anyway. -- Zac67 (talk) 20:07, 29 September 2011 (UTC)


 * Yes. Although this article is about the interface to the media, not the cables. What I was trying to say is that there is no MDI-X equivalent in fiber-optic physical layers, so the cables effectively always have an odd number of crosses in them. Except in the even newer PHYs that us bi-directional media where there is also no such thing as crossover, but have specific head ends (upstream and downstream wavelength division multiplexing for example). Anyway we should not use personal knowledge but cited sources. And as for the article, the changes introduced a red link (which I fixed) and more jargon, so might be an "introduction" or more likely a "Wired Ethernet" section; however it still needs a lead section that summarizes  the article body before jumping into details (which should be sourced).  W Nowicki (talk) 22:11, 29 September 2011 (UTC)

Terminology
The terminology used on this page is a little confusing at times.

In some cases "MDI-X" is used, and in others "MDIX" is used.

What is the accepted (correct) usage? I'm trying to justify changing the references in a User Guide and it's difficult to make my point when there's conflicting information like this.

Diddy1960 (talk) 04:48, 20 April 2014 (UTC) David


 * IEEE 802.3-2012 uses "MDI-X", so that'd be the offically correct usage. Zac67 (talk) 09:48, 20 April 2014 (UTC)

What would happen if MDI-X is never defined?
I suggest adding a note or section right after "MDI vs. MDI-X" section. What would happen if MDI-X is never defined? In this case, there will be MDI at both ends and a crossover cable will be mandatory. As a result, only one type of interface, and only one type of cable would be enough. Of course, patch panels should also be crossing to keep odd number of crossing in the path. — Preceding unsigned comment added by Aksu Mustafa (talk • contribs) 21:24, 14 July 2020 (UTC)


 * Remember that WP is an encyclopedia and not a forum. We describe and don't speculate.
 * The key is that straight/uncrossed twisted-pair cabling existed before Ethernet used it and StarLAN had to be designed to work with that. --Zac67 (talk) 05:25, 15 July 2020 (UTC)