This Recommendation describes the interface between the telecommunications network and the customer installation in terms of their interaction and electrical characteristics. G.992.4 allows thetransmission of POTS and V-series data services simultaneously with a digital channel over a singlemixed gauge twisted metallic pair. Operation in a TCM-ISDN noise environment is for further study.This Recommendation is structured as a delta document to ITU-T Rec. G.992.3. This Recommendation includes procedures to allow provisioning without the need for “splitters”, typically installed at the ingress to the customer premises. Additionally, power management procedures and link states are specified to achieve power savings at the central office and customer premises.