In some systems, there is no separate I/O card. Magnetic component (transformer) will reside in the same board with the transceiver or LIU chip. If so, there are two different ways to handle the external termination resistor. The figure below illustrates a redundancy scheme where TIP/RING leads are connected after the transformer forming a Y-shaped cable connection. In this case, a Y-cable patch-panel is expected. In normal applications, it is recommended that the external termination resistor be as close to the chip as possible. However, with proper layout placement and impedance control, and Y-cable length being less than 1ft, both lab test and simulation indicate acceptable results. Refer to application note AN-858 for more details. For other questions not addressed by the Knowledge Base, please submit a technical support request.