This Recommendation provides guidance on the effect of talker echo and its control. Talker echo is considered independently of all other impairments. Furthermore, the conjunction of talker echo and the E-model of ITU-T Rec. G.107 is explained as well as the reference to ITU-T Rec. G.108.2 on transmission planning aspects of echo cancellers is provided. Previous versions of this Recommendation included a clause on stability that has been deleted because modern networks are largely all four-wire. Earlier versions of this Recommendation contained several planning rules for connections with echo control devices. As many of those rules are now obsolete, they are not reproduced here. A new Appendix III on the Combined effects of talker echo in the presence of absolute delay has been added.