Figure 2.8 shows three Relay nodes: Q, R, and S. The three nodes that support the Friend feature are N, O, and P, however N does not have any friendships; therefore only O and P are Friend nodes. There are five Low Power nodes: I, J, K, L, and M. Nodes I, J, and K have P as their friend, while L and M have O as their friend. Node T is only connected to the mesh network using a GATT bearer; therefore S must relay all messages to and from T.
For example, if a message is to be sent from T to L, then T will send the message to node S using the GATT bearer. Node S will retransmit this message using the advertising bearer. Nodes H, R, N, and O are within radio range of node S; therefore they will receive this message. Node O, being the friend of node L will store the message, and if the message was a segmented message, node O will respond with an acknowledgment at the lower transport layer. Sometime later, L will poll node O to check for new messages, such that O will forward the message originally sent by T to L.
