Message routing path

[zyra102388]

Hi. I am new to Thread. I want to ask how does the Thread network route a message. Please refer to the image attached.
Supposed End Device A will send a message to End Device B. How will the message be routed?

1. From End Device A -> Router 1 -> Router 2 -> End Device B
2. From End Device A -> Router 1 -> Thread Leader -> Router 2 -> End Device B

[jwhui]

Thread routers implement shortest-path any-to-any routing.

Assuming the link costs are all the same, packets from A to B will follow: A -> 1 -> 2 -> B