The NLP (Non-linear Processor) removes any residual echo that may be left over after Echo Cancellation does its calculations and filtering. NLP replaces the residual echo with a low level of "comfort noise" which is computed from the actual level of background noise in the speech. The comfort noise audibly masks the residual echo. NLP may not be required in a managed LAN, but should be helpful if VoIP calls are carried over the WAN.
There are two operating modes for NLP: Adaptive and Fixed. With Adaptive NLP, the level of the comfort noise is constantly adapted as the level of the actual background noise varies. With Fixed NLP, the comfort noise level is not changed after it is initially set up. These options are set in 1814-04: NLP Noise Mode [System: VoIP: Profile (1-4): Echo Canceller (1814): NLP Noise Mode].
| Option | Description |
|---|---|
| No (0) | [Default] Disabled |
| Yes (1) | Enabled |