This Recommendation defines the inter-operation of two PSTN to IP Network gateways that facilitate the end-to-end connection of analogue text telephone terminals over an IP network utilizing text relay. Amendment 1 introduces Annex E, which defines the RTP payload format for the transport of text as T.140 character data over IP networks, removing the need to make a reference to an historic RFC published by the IETF. It also includes minor editorial changes throughout the document to make references to the newly introduced Annex, removing references to the RFC.