In order to compute the ETX of a link, the link quality (LQ) and the neighbor link quality (NLQ) are used. The link quality (LQ) can be seen as the measured probability that data packet originated at a given node (e.g., A) successfully arrives at a subsequent node (e.g., B). The neighbor link quality (NLQ) is a measure of the quality of the link in the opposite direction, i.e., how many of data packets that were sent from B are received by A.