topologies (1 Viewer)

[jake2.0]

i got a couple of questions for you all

1. in a ring network does the data flow only one way or can it flow both ways?

2. a ring network is considered slow right?

thanks

 

[rach_1]

Traffic can be one-way around the loop or can travel in both directions if a double loop is used. Thats what it says in my text book.

Im not too sure about the speed of ring topologies sorry.

 

[steelite]

Ring network=data flow in ONE DIRECTION.
And yes it is considered slow because it has to move from device to another before it reaches it destination.

I always thought it was slow due to there only being one token ring where you could data on and that had to be shared around the whole network.

 

[Original_Angel]

i got a couple of questions for you all

1. in a ring network does the data flow only one way or can it flow both ways?

2. a ring network is considered slow right?

thanks

A ring network only allows for data transmission in one direction - to prevent "clogging" up the network (that's got more to do with the token ring - but that's another story..)

The speed of ring topologies are slow in comparison to the BUS and STAR networks - however, in saying that - they aren't like super slow. You've got to remember that they are stacks fast - just slower than the other two =P (this kinda confused me for a little while)!

Good Luck

 

[BrentMcKendrick]

Hey,
Just to shake things up a little bit...
Lets for example consider a network in which there are say, 140 nodes all connected within a very close proximity of each other. What would be faster:
a Bus (using CSMA/CD) or Ring topology (using Token) if all nodes want to transmit ALOT of data at the same time? (i.e. high load)

You may not have guessed but the answer is indeed Token. Why?? because in CSMA/CD the collisions and the exponential backoff counter (the time the node waits before checking if the line is free again) will add to the transmission of time of each packet. By the time the token has gone around the ring enough times for all data to be sent, it is very likely that the Bus network is still fixing up all the collisions.

i.e. the point im getting at here is that the ring topology is not slower.. it all depends on the load on the network, the amount of nodes and the distance of the ring. (Main factor: DISTANCE OF THE RING, and the time it takes to traverse it).

And also the ring network topology in unidirectional, meaning one way only. This is needed, otherwise the advantages of the ring would be useless.

 

[JTN]

140 nodes all connected within a very close proximity of each other.

roughly how many tokens would be in that token ring?

would it just be one?, if it is, then surley a star network using a switch would be quicker, or would it?

now im confused

 

[WAFFL35]

Hey,
Its BrentMcK here just on my bros account.
In token ring, as i am aware, there is only one token. However it CAN have many slots within the one token frame. (i.e. can hold more than one frame from say A to B, and another frame from C to D), but it is all in the same token frame. I guess if there was more than one token you could have possible collisions so i dont think it is done (check me on that, but im pretty sure).

A star network with a central switch would probably be faster (however you need to make sure the switch can keep up with demand, especially on a network with 140 nodes... the best way to do it would be to split it up into a few star subnetworks connected to each other through the switches to a central router or backbone).

Is it faster? if the router/switch can keep up with demand and the ring topology propogation time (the time it takes to traverse the ring to the destination) is more than the time from station-to-switch-to-station then yes it would be faster.

just to confirm the (SWITCHED)star and ring topologies have no collisions.. if you think about it it makes sense. however the bus and (HUB)star topologies do. Oh and by the way bus setups and still considered faster than ring so write that, but add "it depends on the amount of nodes and the length of the network span (..eg 100 meters).

 

[JTN]

However it CAN have many slots within the one token frame. (i.e. can hold more than one frame from say A to B, and another frame from C to D), but it is all in the same token frame. I guess if there was more than one token you could have possible collisions so i dont think it is done (check me on that, but im pretty sure).

i don't understand the token fram thing but wouldn't it be possible to have more then one token, provided that they all go in the same direction there should be no collisions right?, because the token has to go to every node anyway, so they're all going the same "speed"?

just to confirm the (SWITCHED)star and ring topologies have no collisions.. if you think about it it makes sense. however the bus and (HUB)star topologies do.

wouldn't it be possible for a collision to take place if something like computer A is try to retreive a file from Computer B, but computer C requests a file from Computer A at the same time?, hard to explain what i'm talking about but basically the computer is already sending and receiving data from another computer.

Oh and by the way bus setups and still considered faster than ring so write that, but add "it depends on the amount of nodes and the length of the network span (..eg 100 meters).

I've been told by my teacher that a physical star network with a switch is accutually a logical bus network and that there is no logical star network, only token ring and bus, is this right?