why is Token ring expensive than ethernet

With new 100 Mb ethernet NICs running under $10, token ring NICs would have to be much cheaper. You'll also need the MAU (passive hub) to make them work.

Further, latency's a bitch.

The main benefit of Token Ring has always been that it was the Official IBM Way, however even IBM has abandoned it.

The cost was always due to IBM's license fees and not to anything inherent in the network. And like everything in the PC market from which IBM attempted to extract royalties, it failed in the market.

If you want some TR parts you can probably find someone giving it away, though maybe you would pay shipping. Price them on eBay.

Sometimes Fry's has 1000baseT cards for less than $10 now.

I bought a five port 1000baseT switch for $30 from Fry's.

-- glen

Not until flow control. It is too easy to overflow the buffers in the switch if you run ports at 100%.

Consider a server with a few clients, and each client sends at 100% to the server. The link to the server is now at 300%. Oops.

-- glen

One advantage to some, is that you knew the maximum time a computer had to wait, before sending. You didn't know, with unswitched ethernet. It also supports far larger packets than ethernet.

Deterministic degradation, they call it. Arcnet had the same. Arcnet advocates would tell you that 2.5 Mb/sec Arcnet drastically outperformed 10 Mb/sec Ethernet in LANs with four PCs running Word Perfect due to this.

People that run large networks look beyond the $10/nic cost and pay attention to the ability to manage a network and diagnose and fix problems.

IMO until managed ethernet UTP hubs came on the market TR had Ethernet beat hands-down for wiring to the desktop based on MTTR/MTBF. Even then, the ability for IBM SNA-based managenent to identify faults down to the desktop and dispatch the right repairman was impressive. A FDDI ring beat either TR or ethernet for the building backbone.

To this day I'd pick TR over thinwire ethernet for a large business LAN where MTTR/MTBF and manpower costs were important.

That's kind of like saying you'd pick a Silver Ghost over a Model T. If those were the choices then yes, it's the right one if you need reliability. But if you throw a 2005 Toyota into the mix . . .