Innkeeper 4 squeezes four independent digital hybrids in a 1U rack space. The front panel keypad, display, and handset jacks provide easy speed dialing and call setup. Its excellent caller audio output does not exhibit the transmit/receive crosstalk common to analog hybrids. This makes innkeeper 4 perfect for radio or television talk shows, teleconferencing, or auto-answer IFB feeds. The Digital Signal Processor (DSP) continuously monitors both the phone line and audio signals to deliver excellent separation. This proprietary, dual-convergence echo canceller algorithm can achieve excellent separation, typically exceeding 50 dB, without any setup and without sending a noise burst down the line.