Noise test Noise is the measure of unwanted signals in the transmission path. After the call is established and while the far end is silent, the Branch Gateway collects the noise level.

Receive-loss test After the call is established and while the tone (or tones) specific to the responder sequence is being received, the Branch Gateway collects the signal level at the reference frequency and compares it with the reference level. The difference in decibel between the level sent and the level received is the loss.

Crosstalk test While the analog port under test is in a call and both ends of the call are silent, the crosstalk port establishes another call and plays a sequence of tones. The Branch Gateway collects during that time the tone level for different frequencies on the port under test.

Balance test This test measures trans-hybrid loss. After the call is established and while the far end is silent, the Branch Gateway transmits a tone and measures the reflected signal level. The transmitted tone level minus the reflected tone level is the trans-hybrid loss at that frequency.

Match test This test matches hybrid balance. Stored in the integrated analog testing firmware is a group of hybrid balance coefficient sets. Each entry in the group balances the hybrid against a different loop impedance. The match test executes a balance test for each set of coefficients and determines which set best matches the loop.