Networking

Does anyone actually still USE Token Ring?

One of the big technology battles of the 80's and 90's was Token Ring vs. Ethernet. Even though it was technically superior, Token Ring was overpriced and ultimately fell by the wayside. Here's a recap of Token Ring's advantages, and we ask whether Token Ring is even used anymore.

In an alternate universe, I'd probably be a History Professor somewhere. The launch of the Classics Rock blog has given me the opportunity go take care of the history part, but at the same time, I've been lucky enough to serve as an Adjunct Professor for ITT Technical Institute here in Louisville as well. I've been teaching mostly networking classes lately and I keep noticing a consistent theme in the courses. Every course has spent a non-insignificant part of the curriculum discussing Token Ring. Once the center of a great technical debate in the 80's and 90's, the Token Ring vs. Ethernet wars are long settled. But it's kind of surprising that Token Ring is still taught.

The text for the class calls Token Ring the "second most popular technology" for connecting local area networks. Which, I explained to the class was like saying that traveling by ship is the second most popular way to go to Europe. Yeah, it can still be done, but almost nobody does so anymore.

Token Ring revisited

Token Ring was developed in the early 1980's by IBM as a way to connect PCs together. It was a direct competitor to the Ethernet standard that we use today and the ARCnet standard that disappeared in the mid-80's.

If you remember your network topologies, Token Ring was a ring technology whereby data went from one computer to another in a ring format. Most often, rather than direct connection from computer to computer, you'd locate a MAU in a central wiring closet and then run lines back to each computer. A MAU is IBM-speak for Multiple Access Unit and they were roughly analogous to a switch today. The ring would actually function inside of the MAU. So you'd have a logical ring working with a physical star topology.

Token Ring presented some significant technological advances over Ethernet. There was a huge debate in the 80's and 90's about which technology should be used. As we know now, Ethernet won, but if you just looked at the specs, there was no reason why it should have.

First, there was the way that both technologies allowed computers to communicate on the network. Ethernet uses a thing called CSMA/CD, which essentially means that each computer waits before it transmits on the line. If noone else is talking, it transmits a packet. If by chance another computer transmits at the exact same time, a collision occurs, no data transfers, and the two computers wait a random amount of time before transmitting again. By contrast, Token Ring passes a token around the network that grants computers the right to transmit. If a computer doesn't have a token, it has to wait until the token is freed. This ensures that no two computers can try to access the wire at the same time, making bandwidth usage more efficient.

Second, Token Ring allowed for larger packet sizes than Ethernet. The maximum packet size you could have in an Ethernet frame was 1514 bytes. Token Ring packet sizes depended how fast your line speed was. If you were running Token Ring at 4 Mbps, you could have a packet size of 4550 bytes. If you ran Token Ring at 16Mbps, you could have a packet size up to 18,200 bytes long. Obviously, larger frame sizes mean that you could transmit more data in each packet, reducing the total number of packets on the wire. This lead to less congestion in routers and network cards.

Finally, you had the line speed advantage of Token Ring over Ethernet. Even though Token Ring only first shipped at 4Mbps speed while Ethernet ran at 10Mbps, because of token-passing and frame sizes, you could actually get better performance out of a 4Mbps Token Ring installation. IBM then cranked the speed up to 16Mbps, which had the added benefit of gaining a marketing advantage. Even if people didn't understand how 4Mbps Token Ring was faster than 10Mbps Ethernet, the 16Mbps speed would overcome that.

If it's so good, why did Ethernet win?

Unlike OS/2 where IBM lost because it didn't know how to market the technology, Token Ring's failure in the market place had little to do with bad marketing. In this case, it probably had more to do with greed and advancing technology. Ethernet grew ever increasingly faster, going from 10Mbps to 100Mbps, to where we are now with Gigabit Ethernet and 10G Ethernet. Even though Token Ring was more efficient - to the point that on an unswitched Ethernet segment 16Mbps Token Ring could still be faster than 100Mbps Ethernet in some cases - eventually the increasing Ethernet speeds overwhelmed Token Ring. Added to that was the fact that vendors started introducing switches which eliminated the problems of collisions which slowed down Ethernet networks in the first place. This completely removed one of the major technical advantages that Token Ring had over Ethernet. Switching and 100Mbps speeds make 16Mbps technology obsolete.

Probably the main reason why Token Ring failed however was pricing. IBM charged too much for royalties to vendors that wanted to produce Token Ring cards and MAUs. This made all Token Ring equipment too expensive. A Token Ring card could cost 5 and 6 times as much as an Ethernet card. Add on the cost of more expensive cabling and MAUs, and Token Ring just priced itself out of the market.

Token Ring vendors tried to increase the speed of the technology to 100Mbps to overcome the Ethernet advantages, but by the time they did at the turn of the century, it was too late. Ethernet had won the day.

Is it still around?

I told the class that chances are they wouldn't run into any Token Ring installations today. If they worked in larger organizations where IBM had sold a lot of equipment, there could still be some Token Ring installations still around. But in smaller organizations or to deploy for new installations? They might as well be taking a steamship to London.

44 comments
slocodemonkey
slocodemonkey

Here it is 2014 and I just interviewed for an engineering position for an office that still has token ring in place.  It's alive!  That being said, they are in the process of moving over to a Cisco based switched network.  Still, token ring has obviously been working for them for a long time.  

kevinwfs413
kevinwfs413

I worked with testing 100 mb token ring in a 24 story building. first 12 floors were 1000mb ethernet and the rest were HSTR, the speed difference was amazing the HSTR was noticibly faster for everything. We had some secure data breeches with employees bringing in their own ethernet wireless routers.Eventually they converted the building to HSTR and the system was secured....they were using it until last year when they contracted HP to upgrade and maintain the network and they completely rewired the highrise to 1000mb ethernet. A friend that works at the building let me know they have had lots of headaches and network downtime since the transition.

jonathan
jonathan

Used broken ring a lot in the day when there was PS/2 out there too. AS/400 was another dino that held on to it for me. Since about 1993 I have not seen it. The cheap alternative - 4 pair ethernet ... could not bother buying so much gear.

cmiller5400
cmiller5400

The local A&P used IBM based POS equipment. It was token ring. I remember working one night where they had to break the ring to remove a register; the techs were sweating it hoping that the ring would come back after they cut the wires...

ericswain
ericswain

I worked for United Parcel Service in there Technical Support Group and up until a year ago everything was ran on Tokenring 4/16mgbt. Using CAU, MAU, and LAM's or as we called it, "The Farm". Using Tokenring as opposed to Ethernet was a little more challenging if you didn't have the proper mapping directory. If a node went out you would hear a clicking sound from the CAU or MAU which meant that the next node was not able to accept the token from the previous node. This may sound like a simple task but when your running over a 900 nodes in 1 center connected to a series of MAU's, CAU's and LAM's you have a full day of trace routing. With the switch to Ethernet, the time to locate the proper node to troubleshoot the issue dramatically decreased and the effciency of the network dramatically increased. Was there ever competition with Tokenring and Ethernet? I think not, we praised the conversion and laugh at IT horror stories about being on the farm. Tokenring although great in simplicity at times was a little too simple, especially when you apply it to networks on a larger scale. May IBM's Tokenring RIP as we move towards better network topography's

jon_saxon
jon_saxon

I remember considering using Token Ring instead of Ethernet back in the late 80s when I found the building already wired with twin-ax cables because the company used IBM System 38s. I also remember finding an ArcNet network running in Department of Commerce in 1988. And I worked on thicknet Ethernet until 1996 at the DOJ. Does anybody else remember "vampire clamps" for thick Ethernet cables? Plus I briefly taught at ITT. Deja vu! Been there, done that. Switching and 100mbps Ethernet kind of resolved most of the problems we had with Ethernet. But, as is so often the case in technology, the problems aren't resolved in elegant fashion. We take a fundamentally unstable software platform like Windows and throw faster CPUs and more memory at it. With networks, we throw more bandwidth at the problem even though we use it very inefficiently. Thankfully, Ethernet is a little more stable than 32 bit Windows. The market doesn't always favor elegance and sometimes brute force and simplicity win over a more "elegant" solution. Betamax, Token Ring, QEMM-386, DR DOS. The market is full "better" products that didn't last.

dtilley
dtilley

Great article and a nice trip down memory lane. I have taught similar classes at ITT Tech campus and enjoyed reliving my networking youth. One comment on the idea that token ring makes "bandwidth usage more efficient". The efficiency of either Token Ring or Ethernet is directly related to the type of usage of the network, not those specific technologies. The operational difference is that Token Ring is deterministic, while Ethernet is not.

martin.cox
martin.cox

Token Ring lost out to Ethernet primarily on cost. The Token Ring NIC required a high level of functionality, all cards had to be capable of running the ring and its management functions and was always more expensive that Ethernet. Ethernet was simpler and thus cheaper. Token Ring worked well in SNA environments with mainframes but the introduction of distributed systems and TCP/IP lead to the demise of SNA. The capacity advantage of Token Ring was negated the introduction of LAN switches and higher speed Ethernet

hugh
hugh

I remember as an electrician making the twin axial ends off...gold to spot I think.

hottie89
hottie89

ITT Tech has books with words in them. ITT Tech also has dry erase boards and several colors of dry erase markers. They even have chairs for the students to sit in. It must be a real school capable of providing marketable skills. I hope those ITT Educational Inc. MBAs are right; we all go to heaven no matter how much pain we cause in this world.

dmarston
dmarston

I think you answered your own question. The reason it is still taught, is because it is still in use in some large orginizations (that in turn have lots of employees) that spent millions to put it in place. So consiquently, a student should still know the basics when they hit the job market and potentially get a job working for one of the said large orginizations.

Jaqui
Jaqui

for the steamship. ;) sorry, in the case of travel, Luxury beats speed for me. :D I taught myself networking using a token ring. 6 systems, two of which were working as MAUs. [one for fail over. ] you know what's odd, I think I still have some old ethernet cards with tokenring support, including the connectors

John Sheesley - TechRepublic Pro
John Sheesley - TechRepublic Pro

As I mentioned in Classics Rock, http://blogs.techrepublic.com.com/classic-tech/?p=115 one of the big technology battles in the 80's and 90's was that of Token Ring vs. Ethernet. Arguably Token Ring should have won from a technical perspective, but IBM priced it out of the market. We used Token Ring at the Jefferson County Police Department, but that was after a bid on a network that IBM won. Outside of large organizations, I don't think you'll run into Token Ring anymore nor do I think anyone's doing any new Token Ring installations. Anyone out there still using it?

ydoucare
ydoucare

@kevinwfs413 That would be the fault of the people installing and configuring the network, not a fault of the technology.  We don't seem to have any of those troubles.  It's funny when people that don't know what they're doing just blame the technology.  Weird how that works isn't it?  If you have people that know wtf they're doing, stuff seems to work just fine.  You are probably the type that rejects change and is stuck in the 1980's because you're scared to learn something new, right?

jonsaint
jonsaint

When the AS/400 debuted in 1989 (?) it did not support Ethernet nor did it have an asynch capability. So 3IC customers had to buy into Token Ring and if they wanted their applicaton to drive another device, such as an optical juke box, they had to buy a little S/36 to sit next to the new box and house an asynch card for it.

HAL 9000
HAL 9000

At this place they put up an extension in a Prefab concrete building and somehow managed to catch the single cable in that wall with a Tiger Bolt and crush it. Of course it didn't cause any problems straight away but a few weeks latter when the entire LAN Crashed it took ages to find the problem cable. If I remember correctly it took about 3 hours to track down the problem and about 30 minutes to replace the 1 Cable that was killed off by the builders. I don't think that they could have managed to take this out if they tried but as they where trying not to hit anything in an Old 98 Setup they followed Murphy's Law and trashed the entire setup. :D So Thanks I really needed to remember that incident. :( Col

robo_dev
robo_dev

ans also 3COM CoreBuilder chassis-based switches with TR modules. The 3COM gear was SNMP capable and had anti-beaconing circuitry that worked well. 3Com made both 'smart hubs' and Token Ring switches...all good stuff. It all used standard Cat5 wiring, and was very stable and reliable. Like the old betamax versus VHS debate, Token Ring handled busy network loads better than 10BT and had very good latency and throughput. Of course cheap switched fast ethernet blew it out of the water. Some companies, including IBM, were pushing 'fast token ring' that ran at 100MBS. Cisco made 802.11 Wireless Access Points that had a Token Ring interface. Aironet 340 TR, I believe.

catseverywhere
catseverywhere

I don't know if the guy was pulling my leg, but a friend told me his military-industrial complex "skunk works" office uses token ring. He said is was less prone to EMP interference originating from the outside, (aka "attack") and is harder to sniff with advanced techniques like reading EMP spewing outward generated in various parts of the hardware. But from other appearances I've gotten from this guy over the years, I'd sooner believe it's purely "it works, why spend money to replace it?" at work here.

jonsaint
jonsaint

I never worked directly in that area, but I seem to remember that Ethernet would perform adequately over cheaper wiring than Token Ring. Also there was something about paying royalties to some Dutchman who had patented the idea of the token technology even though he never released a product. When IBM decided to re-wire its own buildings in the late 90's and early 00's, we had to carry both TR and Ethernet adaptors in our luggage because we never knew what we'd find at our destination.

leemond
leemond

God, how I loathed twinax! Fatter than 415v electrical cable and as flexible as a steel girder. And the fact you needed to run two of these stupid fat cables to each terminal. Those ridiculous switched wall connectors, you could guarantee some fool would turn the switch and drop the entire network, which then required an RPL on the AS/400. I was so glad when I discovered the baluns that allowed me to run them over structured cabling!

John Sheesley - TechRepublic Pro
John Sheesley - TechRepublic Pro

Perhaps, but I wonder at this point if many of the large corporations that initially bought Token Ring years ago still have it around. I would suspect over time the vast majority of it has been ripped out and replaced, especially as new workstations have been introduced. I can't see many businesses investing in Token Ring cards and going to the time and trouble to install them when so many new workstations come with Ethernet on-board. I would have thought that IT would rip out the MAUs instead and put in switches. Especially if they were already running CAT 5.

JR256
JR256

We migrated to Ethernet 10/100/1000 a few years ago and have enough HSTR gear to support a company of 500 users in storage. Any one interested? Also have the transparent bridge to 10/100 in the core chassis. Just come get it, no charge...

DL
DL

We recently moved our office and did some house cleaning in the process. We tossed a few new still in the box MAU's and type 1 cable. We hadn't installed any of this for at least 9 years. I have visited many different facilities and haven't seen any token ring out there recently. How many companies still have thin-net , cheaper-net - RG58 coax, This cable was every where 15 years ago, it also was a pain if not installed properly and most of it wasn't. 95% of the issues with this cable was the connectors not installed properly and help desk telling the end user to wiggle the connector. This was a cheap way to wire a network 15 to 20 years ago.

HAL 9000
HAL 9000

It was a decent sized job in a place that makes Electrical Generation Equipment for the Power Generation Industry. All their manufacturing equipment is Computer Controlled and uses the Token Ring System. Works a treat as well I might add even if they are effectively using DOS for all the Manufacturing side of the business. There the Token Ring remains Totally Divorced from the Ethernet Network and they are more than happy with it. I don't think any of the Computer Controlled Equipment even comes with Ethernet as a option. Col

smlaux
smlaux

Token Rings are still in use by system developers requiring time and/or security sensitive communications. Ethernet protocols, before IPv6, have not provided the necessary guarantee to keep that aircraft in the sky or ensure the COCOMs are able to maintain secure communications. Since few commercial communication product providers are supporting IPv6 yet, token rings will remain until guaranteed on-time, no-loss message delivery is available via IP.

debuggist
debuggist

UPS was slowly transitioning to Ethernet in the early '90s. This is a company that held on to OS/2 well after everyone else shelved it. And that's only because they followed Gartner's advice. I'll never forget when I heard they wanted IBM to hack the TCP/IP stack for OS/2 for some obscure reason. Eventually, UNIX, Ethernet and Windows took over there but not without a fight.

robo_dev
robo_dev

I haven't seen any in the past five years here in the states. So I guess my Network General Sniffer Token-Ring adapter, my IBM Redbook on Token-Ring, and my 'Type 1 cable tester' need to be buried at sea? Ahhh the joys of beaconing, the thrill of going from 4MB to 16MB, the IBM 'boy george' connectors. Don't get me started about getting the right adf file for the IBM MicroChannel 16/4 adapter and using DXMA0MOD.SYS...... Surprisingly, Madge still makes the stuff....

robo_dev
robo_dev

Does your friend have a tinfoil hat also? At the mac layer, Token Ring is no better or worse than Ethernet from either a EMP or Van Eck style attack. The 'security through obscurity' argument does not hold water. A strong EMP is gonna bonk anything that uses digital circuitry, whatever the topology. Yes, I'll admit that since an old MAU or CAU only has relays, so they could probably work during a nuclear attack..... Some Military Contractors have a lot of legacy stuff, and their 'feast or famine' funding model leads to some really weird infrastructure.

norin.radd
norin.radd

You are brillant John Sheesley, very good answer

leemond
leemond

Yes, that's pretty much what happened where I worked. I'd spent two years perfecting a fully redundant Token-Ring configuration on a large chemical site, only to rip it out and replace it with Ethernet a year later. Why? - Every new PC came with a Fast Ethernet adapter installed. - None of the new PCs had ISA slots to take the old T-R cards - A new PCI T-R card cost almost as much as the PC itself - It was impossible to buy internal T-R network interfaces for printers, and the external boxes cost more than the printer did. - The cost to buy new Fast Ethernet switches was less than the cost of maintenance on the T-R kit - I was able to remote manage the new switches properly, saving money in travelling expenses going to site On a big SAP rollout at the site, it actually worked out less expensive to replace the estate than maintain the status quo. It all got ripped out and replaced in late 2003, and was the last of the T-R sites I dealt with. The fact that the switches has Spanning Tree as well meant I could even factor in redundant fibre links using the spare pairs that were released by the T-R infrastructure, and meant that all the benefits of T-R were now covered by Ethernet. The only hard part was getting them to coexist!

NickNielsen
NickNielsen

I know of at least three government agencies (state and local) that were still using Token Ring as of three years ago. The primary hindrance to converting to Ethernet was a combination of bureaucratic inertia (it works, why change it?) and funding (It's going to cost [u]how[/u] much?). The friends I had in those agencies have since moved on, so I don't know if they are still using Token Ring or have moved to Ethernet. I know the last of them finally converted from IPX to IP networking in 2006. Edit: punctuation

norin.radd
norin.radd

I've seen an MAU exhibition at the The National Science Museum of Tokyon, pretty impressive...LoL

JeffDeWitt
JeffDeWitt

As of about six years ago when they sold us at least parts of IBM were still using Token Ring. After the sale we changed buildings and for a while some of lost are cubes and were working out of a conference room, Token Ring PC Cards were a hot item!

Magic Alex
Magic Alex

Aside from descriptive slides in my college Infrastructure classes. I understand how it works but i'd probably fail horribly if i had to work on one

robo_dev
robo_dev

really requires things that go boom and leave big mushroom clouds.

jon_saxon
jon_saxon

Well, some cables used with TR were STP with a braided shield. In theory, this might have provided some protection against some kind of EMP. But, unless the entire facility was hardened protecting the cables won't do much good. And hardening a building and everything in it is a bit expensive. If he has clearance he shouldn't be telling you ANYTHING about the inside of his buildings, networks or computers. That is just common sense.

catseverywhere
catseverywhere

Yeah, this guy is a real character. He's always yanking my chain, which he does brilliantly because he's a first percentile genius. He's got some kind of 'clearance,' so I should assume e's never going to tell me anything accurate about what's going on in the facility. So I insist anyway and he gives me hooey like that to get me off his back... yep Next time I'll assume the opposite of what he tells me. I did suspect they were using token ring because it's been long paid for and plain works.

Rudeboy1005
Rudeboy1005

A bit late in replying, but I am currently working on a system which is based on a Token-Ring network. The system is large and old - I'm unwilling to expose which system for commerical confidence reasons, however, if a system was introduced many years ago and is saftey critcal the saftey approach is - if it aint broke dont fix it!

jtaylor3678
jtaylor3678

The exams are why it is still in the textbooks. I'm at ITT grad myself, and we hit upon it briefly with each networking course, but we never picked it apart. It was treated the same way as vacuum tubes and punch cards, really.

mdhealy
mdhealy

Well, I've been doing this a while (my first code was Fortran on punchcards but it's been about 20 years since I last wrote any Fortran, I use other languages nowadays). Never actually seen a Token Ring network though once upon a time I heard of them...

John Sheesley - TechRepublic Pro
John Sheesley - TechRepublic Pro

The only place Token Ring seems to survive is in the text book and in Certification Exams. Maybe it's on the outside chance a network administrator runs across it in a larger institution, but other than that, I don't see a reason to be discussing it.

Editor's Picks