What's the difference between Ethernet and Token Ring in terms of performance at various traffic levels?

Answer 1

At various traffic levels, Ethernet is the best choice no matter what.

With Token Ring, obviously the physical segment of the LAN is organized in a ring, and there is something called the a Token Frame. When there is no data traveling the ring, this frame "circles it". When a station needs to transmit, it "grabs it" and makes it into a data frame for transmission. You can also set different priority levels for different devices. Higher priority means it will take priority over lower devices in the event they both want to send. Since this is limited to 1 host sending at a time, the speed is not going to be there.

Ethernet uses Carrier Sense Multiple Access with Collision Detection, (CSMA/CD). This forces hosts to “listen” to the Ethernet prior to sending so it makes sure that no other host on the segment is transmitting. When the Ethernet segment is not busy, the device that wants to send data can do so. The sending host will then continue to listen, to make sure that sending the data does not result in collision.

If a collision is heard, both of the senders will send a jam signal over the Ethernet. This jam signal indicates to all other devices on the Ethernet segment that there has been a collision, and they should not send data onto the wire.

Answer 2

Depends on different factors. First off Token Ring is more or less dead from a market perspective.

During TR's hay day, Ethernet maxed out at 10Mbps (10Base?) and used only shared access, i.e. hubs. When used in the shared CDMA environment Ethernet is not efficient at all, the best you can hope for is 30% utilization. Once the traffic level gets to high there are so many collisions that it become unusable. Also at this time, Ethernet was half duplex, meaning you could only send or receive not both at the same time. (T1 circuits - for example, both send and receive at the same time 1.5Mb up, 1.5Mb down).

Ethernet has since evolved to use switching technology where only the two devices trying to communicate with each other are "connected" to each other. (somewhat meaningless if all workstations are trying to get to the same server/router), and switched Ethernet also supports full duplex, meaning you can receive and transmit at the same time. In this type of topology the utilization is closer to 100%. Ethernet has also evolved to 100Mbps, 1Gbps (current commonly found port) and 10Gbps (commonly used for trunks).

Token Ring, topped out at 16Mbps. TR is highly efficient, because every station needs permission to send data on the ring. They can't arbitrarily send packets like Ethernet.

So if you go back to 1995, TR was the more efficient. If you get a switched Ethernet network running full duplex they are equally efficient.

Ethernet is by far and away the cheapest and easiest to set up.