Talk:100 Gigabit Ethernet
|WikiProject Computing / Networking||(Rated Start-class, Mid-importance)|
|The content of IEEE 802.3ba was merged into 100 Gigabit Ethernet. That page now redirects here. For the contribution history and old versions of the redirected page, please see ; for the discussion at that location, see its talk page. (2013-01-13)|
what is the advantage of 40/100 gigabit ethernet
over simply using link aggregation with. I'm guessing it's higher efficiancy due to a better distribution of data between links but I'd like to see it mentioned in the article given that most of the 40/100 gigabit ethernet standards simply seem to be based on multiples of the 10 gigabit stuff. Plugwash (talk) 22:12, 22 April 2009 (UTC)
- it should be noted what the difference between 40 gigabit and 100 gigabit is. —Preceding unsigned comment added by 18.104.22.168 (talk) 05:26, 18 July 2009 (UTC)
http://www.networkworld.com/news/2009/042009-terabit-ethernet.html —Preceding unsigned comment added by Simbad87 (talk • contribs) 15:56, 2 December 2009 (UTC)
merge IEEE 802.3ba
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It looks like that was already archived? So just change the "deadlink=no" I suppose. The same info is still on the site, but they came out with more products, see this page.
- There is, as yet, no commercially available PMD Layer 1 compliance test equipment for the 10 Gb/s multi-lane PMDs: 40GBASE-xR4 and 100GBASE-SR10. Most existing 40G and 100G test equipment is for verification of higher-level protocols. L1 capability is usually limited to bitstream BER, and cannot evaluate transceiver conformance to PMD optical and electrical specifications contained in IEEE 802.3ba, which includes eye mask, jitter tolerance, Transmitter and Dispersion Power Penalty (TDP), and Stressed Receiver Sensitivity (SRS), among others. Broad-based physical layer test capability may be prohibitively expensive due to the number of PMDs, and to differences between the unique methods created for 40- and 100GBASE- as compared to existing 10GBASE- methods, despite the same bit rate. PMDs differ, too, in wavelength (device technologies), number of lanes, fiber types and break-out methods. 100GBASE-LR4 and -ER4 test equipment, operating at 25 Gb/s, is not applicable to the 10 Gb/s PMDs. Absent commercially-available equipment for the shorter reach, lower-cost, and higher volume PMDs, users may revert to existing 10GBASE- test methods.
... given that every term and and concept is used in the IEEE 802.3ba 40/100 GbE standard, or was used to describe capabilities of previously cited products. This jargon comprises specific compliance requirements of the IEEE standard, which themselves derive from normal practice by those skilled in the art of serial communication links. Citations of 802.3ba sections and paragraphs can be added, if required [how many, and how specific should they be?], but removal of factual content was unjustified. One might hope that technical vs. editorial/procedural expertise is not sufficient justification for censorship.
- Do not follow that comment either. The Wikipedia:Verifiability guidelines say "Anything that requires but lacks a source may be removed". Now since "you cannot prove a negative", statements like "There is, as yet, no commercially available..." cannot be proven, so therefore sound like personal opinions. Very dated ones at that, since if any such product does come out, the statement would become false. Such a statement might be true at the time you add it, but it is not encyclopedic. As for jargon, remember that people read these articles because they do not know the subject matter already. If they already knew it, they would not need to read the article, right? And if the statement is just generally giving engineering practice, then it does not seem specific to this technology. For example, there are multiple PMDs for 10 Gigabit Ethernet and Gigabit and every other speed too.
- Ah, a line that was added by anonymous user at the same IP address 22.214.171.124 might help explain it, I think. Maybe that the testing products available are intended to test switches and network interfaces, not the transceivers themselves? That might make sense, maybe as an intro to this section. After another quick look at the JDSU news release, it is till not clear to me what was being "introduced". It says "JDSU offers a complete solution for transponder characterization" but hard to tell if that is just a marketing brag. Anyway, the testing part is probably not the "meat" of the article since more readers might be more interested in how "real" the product is and where it tends to be in use. I will try to fill in some other citations. W Nowicki (talk) 19:34, 24 June 2011 (UTC)
- You are correct regarding the statement of "previously cited products." I was referring to the list of Ethernet protocol test equipment that had been listed, several of which claimed "L1" capability. The intent of the statement regarding lack of availability of PMD compliance equipment was:
- to stimulate anyone who can identify such equipment to state so, and improve the text; - to highlight limitations of the protocol test equipment laying claim to L1 capability, and - to provoke interest in the need for practical PMD compliance tests or development of surrogates.
- I have searched unsuccessfully for this equipment for nearly a year, concentrating on manufacturers of prior generations. The industry is in need, but equipment manufacturers have privately said it is not forthcoming. Lack of this capability can create conflicts in attempts to use the standard, possibly impairing its adoption. The new standard deviates only slightly from existing 10G methods, but sufficiently to obsolete the equipment. At present, users of "Ethernet compliant" transceivers are unable to replicate, verify, or evaluate that claim in a defensible manner, that is, in accordance with the standard. I want to raise awareness of this situation.
Conflict in Physical Standards section
A table at the beginning of the section lists the standard that applies to 7 meter copper cables and that is the only copper cable entry. Shortly after that table, it says: The 10 m copper cable objective is met with 4 or 10 differential lanes using SFF-8642 and SFF-8436 connectors. It seems that either the 7 m should be 10 m or the 10 m should be 7 m. Buchs (talk) 19:10, 2 April 2012 (UTC)
- The source cited does not give any information about distances. I have removed both distance specifications. --Kvng (talk) 18:38, 4 April 2012 (UTC)
what does "40G" mean?
- It is just jargon. The people "in the know" use "40G" "40 gigabit" "40GbE" or other variants as shorthand contractions, since the meaning is usually known from context. In Wikipedia the convention is to spell out "40 Gbit/s" (officially with a non-breaking space between the number and units, but that makes the markup less readable). Since the lead explains the contractions "40GbE" I suppose we could use that in the rest of the article, although paraphrasing to "40 Gbit/s" also seems reasonable. But just "40G" seems like a bad idea. Especially due to the over-use of the marketing buzzword "4G" etc. Sources are very inconsistent. Almost all drop the "per second" since it is clearly a rate, using upper case G most of the time, but usually "b" not "bit", but I propose we use Wikipedia rules in the article. Perhaps explaining how the industry is inconsistent with the naming. I see there is a disambig page to 40G (disambiguation) which is fine, but like most disambig pages, any links to it should be changed to spell out the rate less ambiguously. Even then, the rates are somewhat approximate, since various overheads could be counted or not, so can be a little more or a little less that exactly 40 billion bits per second. In general this page still needs much work giving a better context in the lead, instead of jumping right into the alphabet (and numeric!) soup of jargon like IEEE 802.3az SDH PHY etc. W Nowicki (talk) 16:38, 24 June 2013 (UTC)