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Silence Suppression (comfort noise) on non-PSTN call

Third-party call centre application is connected to CUCM7.1.5 via a SIP trunk.  Call centre agents have nailed-up calls to CUCM - incoming calls are connected by the call centre application to the agents (all 7942 phones).  When the agent is not in a customer call, because there is a silent call active to the call centre application, they receive comfort noise which they find irritating.  How can I disable comfort noise, either on a per-phone basis or globally?  All I can find on this is references to PSTN calls and configuring comfort noise on voice ports; that doesn't apply in this case as no PSTN calls are active when the comfort noise is received.


Re: Silence Suppression (comfort noise) on non-PSTN call

Hi Pete,

Hope you are well.

VAD can be enabled/disabled for SIP trunks within the SIP Profile applied to the trunk

Device > Device Settings > SIP Profile

Select the profile applied to your trunk, scroll to the bottom and see if the "Enable VAD" button is ticked.

VAD can be enabled/disabled for phones using the CallManager Clusterwide Parameter (Service) Service Parameter Silence Suppression

Both these are set to off by default though so unlikely to solve your issue.