token ring cards?

[EverythingIBM]

Okay, what do token ring cards do exactly? I know they do something when connected to a network, but seriously.

My IBM has this ancient IBM Turbo 16/4 token ring ISA card in it... and... should I consider putting it back in, or leaving it out altogether? Because if I can't use it for something, I don't really see a reason on keeping it in there sucking power to blink two lights back and forth.

[bladamson]

It was a strange protocol, at least in comparison to good ol' ethernet.

As I recall (and this is recollection from like 15 years ago, so it may well be inaccurate), it avoids network collision by passing a "token" around a "ring" of workstations.  Only the box that has the token is allowed to talk on the network, and all the others can only listen.

Very lord of the flies, it is.  And when you unplug one machine, the whole network goes down (and a rotting pig head falls out of the end of the wire).

[RickyJ]

Yup, it's very susceptible to open circuits, needs impedance matched terminator caps for open cables or T's.

[RoboKrikit]

They are very powerful and impervious to damage, but to use one is to inevitably undo oneself and become lost in greed and anxiety.

[RickyJ]

Haha, that's the Tolkien Ring, not Token Ring.  Although any token ring equipment would surely be destroyed when cast into the fires of Mount Doom.

[RoboKrikit]

Doom, I say!

[RickyJ]

I've always disliked F-connectors, they rarely thread on correctly when you're not looking at them, and some people overtighten them.

[Konrad]

Plus you always seem to need about five different crimping tools, instead of just one.

[mike]

Token Ring is a networking standard that somewhat (OK, largely) predates Ethernet.

I don't believe so. According to Wikipedia, Token Ring dates to 1985 and Ethernet to 1980. It's actually wrong on the dating of Ethernet which dates to sometime between 1973 and 1976. ARCNET predates Token Ring with a similar token-passing mechanism originating in the late 1970s.

Never used them myself, although I did use the similar FDDI - even had an FDDI ring at home for a short while.

[ch_123]

Ethernet was developed by Xerox for the Alto, IIRC.

[NAVIWORLDINC]

It was a strange protocol, at least in comparison to good ol' ethernet.

As I recall (and this is recollection from like 15 years ago, so it may well be inaccurate), it avoids network collision by passing a "token" around a "ring" of workstations.  Only the box that has the token is allowed to talk on the network, and all the others can only listen.

Very lord of the flies, it is.  And when you unplug one machine, the whole network goes down (and a rotting pig head falls out of the end of the wire).

This is somewhat true, Token Ring Networks were an evolution built up from a bus network. To avoid collisions each node would only send information out onto the network once the "token" was passed on to each other. Though token ring networks are not used much anymore, Token connections do still exist, even with fiber and twisted pair cabling. Often in modern token ring networks there will be a device that resembles a switch where all nodes can plug into such as your normal mesh/star network topology, and that switch will control where and when to send the token to each node to allow for communication. Often with modern token ring networks, multiple tokens are used. Also note that not all Thinnet/Thicknet (Coaxial) network cards did not rely on the token ring standard (IEEE 802.5) as they could also be used on bus, star, hybrid and mesh topologies, though because of their limitations of bandwidth, were often used in a token ring type network.

[keyb_gr]

BNC on coax is an Ethernet cabling method as well.

The corresponding coax enjoys a reputation for being quite crappy btw.

And, IMHO, about as superior to modular connectors as anything can be. Far more robust. At the very least it kicks the crap out of F-connectors.

If you want robust, there's still PL. Or N (which also is waterproof).

Modular connectors may not be the very best, but going to balanced (twisted pair) wiring required suitable ones with at least 4 poles (nowadays even . Without these, we wouldn't have gigabit over copper.

[firestorm]

We still had token ring when I started working here.  It would piss me off to have to add a token ring card to computers that already had Ethernet built in.  When we migrated to Ethernet, I had to find impedance matching baluns to connect systems that were still on Type-1 cabling.  

My High School had a token ring network as well (very popular with government entities) and I worked in one of the labs for a semester.  The IT guy I worked with was convinced the whole network would go down if we unplugged a machine.  I never once had a problem with disconnecting systems, even with passive (non-powered) MAU's (TR equivalent to an Ethernet switch or hub.)

I think we finally disposed of the MAU's and cards 3 years ago.

FWIW, we also had Twinax running all over the place.  Until about a year ago, one run was still used to connect an old IBM line printer used for checks and reports.

[NAVIWORLDINC]

.  The IT guy I worked with was convinced the whole network would go down if we unplugged a machine.

This would be true in scenarios where it was a physical ring topology where each node connected to its neighboring node, making a physical ring. However like I said that method has been pretty much been thrown out, as there are devices (for the life of me I can't recall the name) that each node can plug into like a switch that controls the flow of the token ring(s). I assume where you were had.

[JBert]

Very lord of the flies, it is.  And when you unplug one machine, the whole network goes down (and a rotting pig head falls out of the end of the wire).

Ehr, no. There is normally one "Active monitor" who is responsible of checking that no evildoer starts creating tokens or drops one. If that monitor goes down, a standby monitor will take over that role, etc.
Also, Token ring had something alike to "hubs" (IBM called it a Media Access Unit) which were actually switchboxes with relays in them - cutting a wire would drop power in the relay and close the loop again.
If you didn't use one of those MAUs to keep a continuous ring structure, then obviously you are on your own for managing the loop and disconnecting a station would indeed bring down the network.

On a final note, classic token ring used a "hermaphroditic connector" and not one of those BNCs. Unless such a connector broke, you couldn't mess with it. Only Ethernet over coax needed a terminator.

This would be true in scenarios where it was a physical ring topology where each node connected to its neighboring node, making a physical ring. However like I said that method has been pretty much been thrown out, as there are devices (for the life of me I can't recall the name) that each node can plug into like a switch that controls the flow of the token ring(s). I assume where you were had.

Heh. You were just talking about the Media Access Unit I mentioned above (I cheated by peeking at Wikipedia).

[NAVIWORLDINC]

Heh. You were just talking about the Media Access Unit I mentioned above (I cheated by peeking at Wikipedia).

I was talking about it on page one too... I don't remember it being called as a Media Access Unit on my CompTIA Net+ exam, but yeah sounds like a good name to call it, especially if that is what IBM named it.

[firestorm]

This would be true in scenarios where it was a physical ring topology where each node connected to its neighboring node, making a physical ring. However like I said that method has been pretty much been thrown out, as there are devices (for the life of me I can't recall the name) that each node can plug into like a switch that controls the flow of the token ring(s). I assume where you were had.

I know, but I meant to infer it is doubtful that my High School wasn't using MAU's (or Media Access Units as pointed out) in 1995.  The IT guy I worked with was a nice enough guy, but he wasn't very technical.

Edit:  Media Access Unit didn't sound right to me either.  It's "Multistation Access Unit".

[NAVIWORLDINC]

Edit:  Media Access Unit didn't sound right to me either.  It's "Multistation Access Unit".

Ahh! That's it!

[Konrad]

I used to work with networks that looked something like this.
 
Too bad they never had any of this sort of tech.

[D-EJ915]

If I ever get back up into the ceiling at this marine mess hall I'll take a pic of this big IBM MAU they have stuffed up in the tiles lol.  I literally laughed out loud ( as well as the other guy who was holding the ladder ) when I found it and also laughed because there were only 2 cables plugged into it which they could have just plugged together instead.

Unless you want to write something which will use the token ring protocol it is basically useless since you can't run TCP/IP over it or anything somewhat useful.

[firestorm]

Unless you want to write something which will use the token ring protocol it is basically useless since you can't run TCP/IP over it or anything somewhat useful.

You can run TCP/IP over it.  We had an NT domain running over TCP/IP with Netbios running on ours.  When we migrated to ethernet, we made a seamless transition using Cisco 2612 routers with token ring and ethernet ports with routes between the two.  I have no doubts that other protocols work on top of token ring (I never tried it), such as SPX/IPX.  It's really only the physical layer that differs.