On-Net Stations to Hybrid PBX Trunks
The diagram below specifies digital PBXs using both digital and analog trunks. The DPBX will use 0 dB TX and RX TLPs for digital trunks. The TX and RX TLPs are -2 for analog trunks. End-to-End loss is 9 dB + ICL. Note that the Tandem PBX inserts loss in one direction, gain in the other.