Talk:Fiber Distributed Data Interface

Removed text
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 75.37.239.179 (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
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

hi
fddi basically based on lan technology —Preceding unsigned comment added by 210.212.159.87 (talk) 03:26, 27 September 2008 (UTC)


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

Maximum ring length
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?
"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. 129.138.32.219 (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
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