Confused about the ring and Mesh network topology?

[Theminecraftaddict555]

So in my practice final exam, I am asked a question saying that which topology increases redundancy by have nodes to connect to other nodes of the network? I had to choose either ring or mesh topology but both topologies have nodes being connected to each other though? So i chose ring and then the answer ended up being mesh? What the heck?! 

 

Is there something I am missing here?

[Mira Yurizaki]

Ring network topology:

Mesh network topology:

The difference between the two is nodes in ring networks only have two connections. Nodes in a mesh network can have as many as feasible.

 

The reason why mesh is better for reliability is that in a ring network, two nodes going down can isolate nodes from each other. In mesh, there can still be a path to another node depending on how many paths there are.

[Shiv78]

IDK this at all but your propic was too nice to not comment on it C:

[squirrl]

The key word is redundancy here. With a ring network, if one connection goes down, then anything past that connection is cut off from the network. A mesh network has multiple connections between machines so if one connection is lost, then the network should still be operational since there are other routes that the traffic can take.

[Theminecraftaddict555]

1 minute ago, squirrl said:

The key word is redundancy here. With a ring network, if one connection goes down, then anything past that connection is cut off from the network. A mesh network has multiple connections between machines so if one connection is lost, then the network should still be operational since there are other routes that the traffic can take.

So pretty much, if one device in a ring network fails, then everything else fails 

 

If one device in a mesh fails, then other devices can simply rely on another path to transmit data to? 

[Theminecraftaddict555]

2 minutes ago, Shiv78 said:

IDK this at all but your propic was too nice to not comment on it C:

Just comment on my profile channel next time

[Theminecraftaddict555]

3 minutes ago, M.Yurizaki said:

Ring network topology:

Mesh network topology:

The difference between the two is nodes in ring networks only have two connections. Nodes in a mesh network can have as many as feasible.

So same thing would apply to this mesh topology too?

[Mira Yurizaki]

Just now, Theminecraftaddict555 said:

So same thing would apply to this mesh topology too?

Yes. Specifically ring means the nodes are connected in a chain like fashion. Mesh is that nodes are connected to each other however the system sees fit. Mesh networks are usually used for wireless communications, if that helps you understand it better.

[zMeul]

27 minutes ago, Theminecraftaddict555 said:

So in my practice final exam, I am asked a question saying that which topology increases redundancy by have nodes to connect to other nodes of the network? I had to choose either ring or mesh topology but both topologies have nodes being connected to each other though? So i chose ring and then the answer ended up being mesh?

wait a sec .. what type of hardline connections are we talking about here

direct network cables between PCs or with switches? because if you connect two switches via two network cables, those two switches will murder each other and the network will cease to function - packet collision 

[Theminecraftaddict555]

13 minutes ago, zMeul said:

wait a sec .. what type of hardline connections are we talking about here

direct network cables between PCs or with switches? because if you connect two switches via two network cables, those two switches will murder each other and the network will cease to function - packet collision 

pc's 

[zMeul]

Just now, Theminecraftaddict555 said:

pc's 

PCs

[Theminecraftaddict555]

24 minutes ago, zMeul said:

PCs

k

[Brightglaive]

Think of every node in the network as if it were a switch or router (like a proxy server if you will). With mesh networking every node in the network is responsible for forwarding traffic to the other nodes. Leaving aside path determination (L3) and (at layer 2) spanning tree considerations, we are talking about the MOST redundant amount of paths to any given node on the network.if you have a ring topology you have one path from one node to the next, to the next etc.

 

Ring topology also has the problem that traffic only flows in one direction. Kind of like a mobius strip or that picture where the stairs seem to connect to themselves in a square but all the while going up (or is it down?) so if one node goes down, so does the whole ring after that one node. but in mesh if you lose one path to a node you still may have 4 others (if we use your diagram with the 6 nodes in a full mesh topology).

 

If you cut the link on the ring topology you only get one path to a node that may have been right next to yours. You cut a link in the full mesh  topology and you should still have at least 15 other paths (indirect though some may be) to get from the node that lost a direct connection to another node. 

 

So which topology increases redundancy by having nodes connect to other nodes of the network?

 

Or a better way to put it. Which topology has more redundant links (and thus paths) to other nodes in the network?

 

2 links/paths are great. 5 links are better.  

 

....and the green diagram is only a partial mesh topology.

 

don't believe me?... label the nodes on your full mesh diagram A,B,C,D,E,F and then cut the connection between A and B. You can still get to B by going A-->C-->B, ADB, AEB, AFB (2 hops), ACDB, ACEB,ACFB, ADCB, ADEB, ADFB (3 hops) etc etc up to a 5 hop path like ACEDFB or ACDEFB.

 

If you like puzzles, try and find how many iterations you can. I can count at least 20 different paths off the top of my head without writing them down.  

The only rules are:

1) you don't go through the same node more than once

2) A is the start point and B (or whichever node you chose) is the endpoint

 

[U.Ho]

7 hours ago, Theminecraftaddict555 said:

So same thing would apply to this mesh topology too?

That's a full mesh.

 

I know this has kinda been said already, but just to pitch in, try cutting any four wires on that topology and you still have a mesh.

 

In a full mesh the number of connections you have equals the sum like this where n=[number of machines]: 

 

That means for 6 nodes you get 0+1+2+3+4+5=15 connections, 7 nodes would be sum for six nodes plus 6 = 21 and so on.

 

If you want to subtract connections from a full mesh, how many can you take away before you lose the mesh altogether?

 

(Why are we doing puzzles? :D)

 

 

edit:

 

Wow, I did that sigma thing all wrong... Here's the correct way to put it:

 

 

 

[skywake]

8 hours ago, zMeul said:

wait a sec .. what type of hardline connections are we talking about here

direct network cables between PCs or with switches? because if you connect two switches via two network cables, those two switches will murder each other and the network will cease to function - packet collision 

Because a consumer grade switch isn't designed for any kind of link redundancy.