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Nit: This is not a mesh. With only 3 nodes, it's not even a ring but just a direct connection between servers.

A "real" ring is formed when you have more than 3 nodes and so some destinations require more than one hop. A mesh implies a network formed by somewhat arbitrary point-to-point connections with multiple possible routes between two points.




Full-mesh typically means each node connects directly to each other node (for some value of directly), so IMHO, a three node system with each node connected to the other two fits the name. I do agree that it's not very interesting with only three nodes.


A network where every node has a direct connection is a point-to-point network. Yes, it is a special-case called a fully-connected mesh, but these networks are rarely made (a fully-connected mesh of 32 servers require 32 NICs in each server and 496 cables) and it is not a common term.

What is usually described as a mesh network (technically: "partially connected mesh") is a network where every node has a route to every other node, and that every node may have a direct connection to any number of nodes, but where there is no guarantee that any two nodes have a direct connection and may need to route over other nodes. The ability to handle this sort of completely arbitrary network topology is the core to mesh networks.

See https://en.wikipedia.org/wiki/Mesh_networking. There's also the old WiFi mesh spec (https://en.wikipedia.org/wiki/IEEE_802.11s, what the OLPC used), not to mention Zigbee and Bluetooth Mesh.


This may not be a ring, but a “real” ring doesn’t require more than 3 nodes. A ring can be formed with as little as 2 nodes.

If routing was enabled this would definitely be a mesh network. It would be a full mesh network where every node is directly connected to each other and a secondary path through another node is available should the direct path fail.


I was speaking from the perspective of a network, where you'd want to distinguish between a direct connection between two computers, and a network where you need to cooperate for routing.

This is not a ring because it is not configured as such: Rather, each network card has exactly one peer, and there is no knowledge of other peers, making it no different from just a direct connection between two computers.

If you had redundant paths, it would be a ring yes. A 3-node routable ring is in theory a special-case of a fully-connected mesh, but you do not call ring networks mesh networks. Mesh is usually reserved for when you truly mean to support arbitrary, disorganized network topologies

See https://en.wikipedia.org/wiki/Mesh_networking


A network where all nodes are fully connected to every other node and data can be routed through secondary indirect paths if the primary direct path fails is absolutely a mesh network.

And a 3 node ring is absolutely still a ring network.


> A network where all nodes are fully connected to every other node and data can be routed through secondary indirect paths if the primary direct path fails is absolutely a mesh network.

Yes, that is a classical partially connected mesh because it functions without a direct connection between all nodes. That you started out fully connected does not matter.

If the network relies on direct connection between source and destination, it is not a mesh.

> And a 3 node ring is absolutely still a ring network.

Only if it can route when you break the loop, and only if you extend it by inserting more nodes into the ring.

The example in this article does not route, which is why it is absolutely not a ring - If you disconnect server A and B, they cannot talk even if they both connect to C. There are just 3 entirely independent point to point networks.




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