ITU-T Recommendation G.108.2 provides guidance for the transmission planning aspects in conjunction with the deployment of echo cancellers in the network. Recognizing that echo cancellers are required on an increasing number of connections due to the increase of end-to-end delay by the introduction of speech processing techniques as well as of packet-based transportation mechanisms, this Recommendation is intended to assist network operators and transmission planners as well as equipment manufacturers and application designers in controlling the effects of echo cancellers on end-to-end speech transmission performance.