Talk:ARCNET

message: I think it is misleading to imply that Ethernet was a proprietary protocol until the mid 80s. The DIX consortium (Digital, Intel and Xerox) published the Ethernet standard on September 30, 1980 (The Blue Book). The intention was to open up implementation to other companies. This work was taken further by the IEEE and the ISO. It was never under the control of 3Com in the way that IBM controlled the Token Ring standard. 
In the late 70s, IBM was by far the largest computer company in the world and its proprietary networking architecture, SNA, was viewed as a grave threat to the smaller companies - the BUNCH (Burroughs, Univac, NCR, Control Data and Honeywell) in the USA and Bull, ICL, Olivetti, Philips and Siemens in Europe. Because IBM controlled the development of SNA, it was always in the best position to exploit new features or to tailor the standard to IBM systems. To counter this, a rival network architecture, Open Systems Interconnection (OSI), was developed as a series of International Standards, starting with the OSI Reference Model in 1979. 
Ethernet was adopted by this group as an open standard for LANs that was not controlled by a single company. Implementation was rapid - I was involved in early ICL developments from 1981. The number of companies involved in developing Ethernet created a large market that encouraged innovation and led to ever reducing costs. This is what effectively killed off ARCNET and Token Ring, IBM's attempt to dominate LANs. John of Groats 11:10, 27 May 2006 (UTC)
thread_title:  Ethernet - a proprietary protocol? 

message: I'm not buying the "Ethernet can collapse at high loads" and "maximum practical load was 40-60%" arguments on this page; I think it's perpetuating the "Ethernet Load Myth" that probably deserves its own page on Wikipedia. The paper that goes into this in detail is Boggs, David R. and Mogul, Jeffrey C. and Kent, Christopher A. (1988), "Measured capacity of an Ethernet: myths and reality", which is referenced from the Ethernet page. —The preceding unsigned comment was added by 125.100.126.202 (talk) 05:11, 26 March 2007 (UTC)
replies: text:  I can't read the paper you've referenced as I don't have an ID on the ACM portal and I'm not going to give up my email address to get one, but it doesn't matter as I am very familiar with this debate and agree that by 1988 10mbit 'flat' Ethernet outperformed ARCnet, even on a heavily loaded network.  The last big flat 10mbit Ethernet I worked on was in the early / mid 90's, it was 900 nodes. 20 - 30% collision rate was a fact of life but even so, actual usable bandwidth was far greater than ARCnet's 2.5mbit.  Of course ARCnet wasn't really even comparable in an environment like that as you couldn't build a flat ARCnet network with more than 254 nodes.  74s181 10:55, 26 March 2007 (UTC)
replies: text:  Anyway, the thing that allowed ARCnet to outperform Ethernet in the early days (prior to 1985 or so) was not the collisions themselves, but rather the latency introduced due to the time it took for the slower processors and less intelligent NICs of the day to recover from collisions.  By 1988 the 80386 was replacing 80286's in servers, the 80286 had replaced most 8088 desktops, most 3c501s had been replaced, and performance was no longer a justification for ARCnet.  Reliability continued to be a major ARCnet advantage until 10BaseT came into common use around 1990, eliminating all the nasty issues you got from putting a T connector on the back of a desktop PC.  Even after that ARCnet continued for a while, slower, but fast enough, and much cheaper, but that didn't last.  Increased demand, manufacturing quantities, and VLSI integration led eventually to the $5.00 commodity 10/100 NIC of today, Ethernet so cheap that server class machines have two gigabit NICs built in whether you need them or not. 74s181 10:55, 26 March 2007 (UTC)

text:  I updated the article about a month ago to more accurately reflect the historical 2.5mbit ARCnet vs 10mbit Ethernet performance issues under heavy load. 74s181 10:55, 26 March 2007 (UTC)
thread_title:  Theoretical and Practical Maximum Performance of Ethernet 

message: The allusion to cat 3 is misleading. Most people assume RJ-45 4-pair (or 3 pair) connectors. "Category 3" refers to data transmission quality, equivalent to high quality telephone wiring. One point in Arcnet popularity is the network cards usually had two RJ-11 (single/dual line telephone) connectors which could be daisy chained or use building telephone wiring with an active or passive hub in the telephone wiring closet. Spare the expense and permits to run plenum wiring in leased space. Had a client with TP Arcnet connecting CNC machinery, the electrical noise in the shop precluding ethernet.
Another oversight may be not noting that Arcnet was generally restricted to Netbeui protocol.  CNE's have told me ipx and even ip could run on it but that has not been my experience. There was a product called Promise LAN or Moses LAN that used Arcnet chips and protocols but had a higher clock.
    
As to speed. (Insert 60mph highway at rush hour story.) I haven't seen a larger arcnet intallation then those factories, but the machinery requires real rime controller response and there were no spoiled parts due to latency. 
Problem with ethernet is that unlike token passing network where the transactions continue (machine sees slower speed but network speed at maximum), ethernet machines resends causes the network to slow down which makes the machine network speed to slow even more. 
When I was at a software support callcenter with several hundred techs, periodically ethernet would breakdown to less than 1 Mbit on 10base and less than 5 Mbit on 100baseT. On the 10base we usually had ip/ipx/netbeui running (many unix systems were still ipx). 100base didn't overload as often.
Shjacks45 (talk) 15:44, 9 December 2007 (UTC)
thread_title:  Needing clarification 

message: The article has much discussion of cost comparisons vs. thin Ethernet, some of which I suspect is WP:OR.  However, none on the cost of cable.  The RG/58 cable used by thin ethernet is fairly common in radio and electronics lab work, and so is often reasonably priced.  (Plenum rated cable is expensive in all cases.)   As well as I know (without doing any WP:OR) RG/62 is more expensive. That could easily make up the difference in other costs. Gah4 (talk) 01:19, 6 October 2019 (UTC)
thread_title:  cost