Talk:Fiber Distributed Data Interface

From Wikipedia, the free encyclopedia
Jump to: navigation, search
WikiProject Computing / Networking (Rated Start-class, Mid-importance)
WikiProject icon This article is within the scope of WikiProject Computing, a collaborative effort to improve the coverage of computers, computing, and information technology on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
Start-Class article Start  This article has been rated as Start-Class on the project's quality scale.
 Mid  This article has been rated as Mid-importance on the project's importance scale.
Taskforce icon
This article is supported by Networking task force (marked as High-importance).

Removed text[edit]

I removed the following text which doesn't belong: "FDDI also uses the 4B/5B digital signal encoding method instead of the Manchester encoding method used by Token Ring and Ethernet. The use of 4B/5B provides nearly the same real world throughput on a 100Mbit link as Ethernet would achieve using 200Mbit." Although it is true that FDDI uses 4B/5B encoding, that detail doesn't really fit in the current article, which is fairly high level. When the article evolves to include lower level details (like the MAC, PHY, and various PMD layers), this would fit in. The second sentence is simply untrue; encoding has no effect on throughput. Indeed, Fast Ethernet itself uses the same 4B/5B encoding method as FDDI! --Rick Sidwell 04:07, 6 March 2006 (UTC)

You may have taken out too much since the article now says FDDI was obsoleted by Megabit Ethernet which gets about the same 100 Mb/s. Ethernet is a collision based protocol and therefore can not transmit at close to 100% because of the need to retransmit whenever there is a collision. (Computers on Ethernet can send a message whenever they can, without regard to other computers on the network.) It runs at 40 - 50% of rated speed. The token networks can run at upwards of 90& efficiency because token methods, only allow one message to be sent at a time across the network preventing collisions and resends. —Preceding unsigned comment added by (talk) 04:48, 30 September 2010 (UTC)

Above comment is misleading. Only the earliest Ethernet implementations had collisions. The Ethernet over twisted pair standards supported full duplex links with switches that provided much more than 100 Megabits/sec of bandwidth total in the network. As the article correctly says, it was the low cost mostly. W Nowicki (talk) 19:52, 28 June 2011 (UTC)

FDDI doesn't use the "token ring" algorithm[edit]

It's a popular but incorrect claim that FDDI uses the token ring (meaing the IEEE 802.5) protocol. FDDI is indeed a ring network, but its MAC (Media Access Control) protocol is fundamentally different from 802.5. Instead, it was adapted from IEEE 802.4 (token bus). FDDI and 802.4 both use a "timed token" approach, while 802.5 does not. Paul Koning 14:49, 23 March 2007 (UTC) Elie Hachache


fddi basically based on lan technology —Preceding unsigned comment added by (talk) 03:26, 27 September 2008 (UTC)

Huh? It is an example of a local area network (LAN) as mentioned.

Maximum ring length[edit]

The maximum allowed ring length is 200 km (by the standards), but you need to pass every host 2 times, meaning the total ring length is actually 100km...(Unless you want to sacrifice redundancy). Maximum allowed hosts per ring is 500, and maximum distance between 2 hosts is 2km. Sorry, don't have a reference by hand to cite from... Aphexer (talk) 14:29, 6 January 2009 (UTC)

Potential copyvio?[edit]

"Figure 8-2 depicts single-mode fiber using a laser light source and multimode fiber using a light emitting diode (LED) light source." This sounds like it came straight out of a print source, making me wonder if the rest of that section is also from that print source. (talk) 06:40, 5 March 2009 (UTC)

It's from a PD source here. - Tbsdy (formerly Ta bu shi da yu) talk 12:21, 5 March 2010 (UTC)

Copyright problem removed[edit]

Prior content in this article duplicated one or more previously published sources. The material was copied from: Infringing material has been rewritten or removed and must not be restored, unless it is duly released under a compatible license. (For more information, please see "using copyrighted works from others" if you are not the copyright holder of this material, or "donating copyrighted materials" if you are.) For legal reasons, we cannot accept copyrighted text or images borrowed from other web sites or published material; such additions will be deleted. Contributors may use copyrighted publications as a source of information, but not as a source of sentences or phrases. Accordingly, the material may be rewritten, but only if it does not infringe on the copyright of the original or plagiarize from that source. Please see our guideline on non-free text for how to properly implement limited quotations of copyrighted text. Wikipedia takes copyright violations very seriously, and persistent violators will be blocked from editing. While we appreciate contributions, we must require all contributors to understand and comply with these policies. Thank you. Moonriddengirl (talk) 01:30, 5 March 2012 (UTC)