Token Ring and Ethernet (1 Viewer)

[honky tonk]

I've tried looking everywhere for a definition of Token Ring and Ethernet in terms of collision, detection and what not, but I'm yet to find one that actually makes sense to me!

Can anyone explain them to me in a "lamen's terms" kind of fashion? Thanks

 

[KAty]

ethernet and ring

ring topology is when msg's are sent and recieved in one direction, from device to device until it reaches its destination
i.e. a ring

Token ring access method is used in conjunction with this topology

I.E. the token ring acess method avoids collision by sending a a token (a data packet) around the network passing each node. When a node wants to send data, it will capture the token and attach data. A token with data cant be captured.
Make sense?

Ethernet is different because it uses CSMA/CD to overcome the problem of collision.
CSMA stands for Carrier Sense Multiple Access. This aviods collisions by make the node listen to the bus for signals, when their is no signal it transmits.
CD stands for collision detection.
When a collision is detected, each device stops transmitting and re transmits at a later time.
Ethernet is used with a bus topology

 

[fatmuscle]

diagrams will help

i think howstuffworks may have a diagram. (an animated one, I could be wrong)

 

[grendel]

here is the howstuffworks link.
http://computer.howstuffworks.com/ethernet.htm

 

[honky tonk]

Thanks guys, much easier to understand now.

 

[rx72c]

Token Ring is pretty simple. If you think about the ring topology as a circle with computers connected on that circle, according to the token ring data can only flow in one direction (For e.g anti-clockwise.) For a piece of data to travel from one node to the next, a free token has to pick this data up and travel in that anti-clockwise direction until it reaches that node. If a node wants to send data but all tokens are busy then it has to wait until a free token arrives. This means that the token ring protocol will never give a chance for any token to hit another token as they all go in on direction at the same speed.

I hope this helps you understand TOKEN RING.

Ethernet is not a bulletproof protocol but more widely used than token ring as Ethernet is used on the BUS topology which is widely used by big corporations for many reasons.
Ethernet uses a protocol called CSMA/CD for error evasion, detection and correction.CSMA/CD stands for Carrier Sense Multiple Action/ Collision Detection. On the bus each computer will look for signals when attempting to send information to another computer, it will wait until there are no signals detected on the bus and then send its information to another computer, the problem with this is that if two computers detect that there is no signal on the bus at the same time and they both send then it is likely that they will collide if travelling in a similar root. Once a collision occurs and is detected a both computers will wait a random time between 2-6 seconds and attempt to retransmit.

I hope that explains it well.