Configure telephony, noise, and call timing for voice AI

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What is the Calling tab?

The Calling Tab is where you configure how your agent handles phone calls. Set up your telephony provider, enable call features like noise cancellation and voicemail detection, turn on Inbound Calling for this agent, and restrict outbound calling hours.

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Configuration options

The settings below follow the order they appear in the Call Configuration card, top to bottom, followed by the Inbound Calling and Outbound call timing restrictions cards.

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Telephony provider

Pick the provider this agent uses to place and receive phone calls: Twilio, Plivo, Vobiz or Exotel. Once your account has a SIP trunk, the Telephony Provider dropdown also lists SIP Trunk. If the account also has a Legacy SIP trunk (deprecated), that one is listed as SIP Trunk (previous).

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Ambient noise

Add background ambient noise to your calls for a more natural, human-like experience. Ambient noise is available for Plivo and Vobiz telephony providers and for SIP trunks. Bolna supports both preset and custom ambient noise tracks. Select a preset or upload your own custom track to use as background noise during calls.

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Preset Tracks

Three preset tracks are available to all users out of the box: Set ambient noise to None to disable it (default).

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Custom Tracks

Use the + button next to the dropdown to upload your own ambient noise track, and the play button to preview the selected track:

• Supported formats: wav, mp3
• Maximum file size: 10 MB
• You can upload, list, and delete your custom tracks from the dashboard or via the API
• Custom tracks are private to your account, while presets are available to everyone

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Noise cancellation

Filters background noise during the conversation, so the agent hears the caller more clearly in noisy places like streets, shops or offices.

• Off by default. Turning it on sets the level to 85%.
• Drag the slider to set the level anywhere from 60% to 100%.

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Voicemail detection

Detects when a call is answered by a voicemail system or answering machine and disconnects the call automatically, so your agent doesn’t speak to a recording.

• Off by default.
• On Twilio, you can also set how long Bolna waits to detect a machine: 2 to 10 seconds in 0.5-second steps (default 2.5 seconds). On other providers the duration field is shown but cannot be edited.

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Keypad input (DTMF)

Lets the caller type digits on their phone keypad, such as an OTP, PIN or order number, and press # to submit. The digits reach the agent as text it can read and respond to.

• Off by default.
• Available with Twilio, Plivo and SIP trunks. The toggle is disabled for other providers.

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Auto reschedule

Calls the recipient back at the time they ask for. If someone on the call says something like “I’m busy now, call me tomorrow at 4 PM”, Bolna schedules a new call to them at that time. Off by default. This is a Beta feature and is still being improved. How it works:

1. After the call ends, Bolna reads the transcript to find the date and time the recipient asked to be called back.
2. If a valid time is found, a new call is scheduled to the same phone number with the same agent, caller number and call details. It shows up with the scheduled status, and the original call’s rescheduled_at field is set to the callback time.
3. If no callback time was discussed, nothing is scheduled.

A callback is not scheduled when:

• The recipient never spoke during the call
• The requested time is in the past or more than 14 days away
• The requested time falls outside your allowed calling hours. The request is dropped, not moved to the nearest allowed time. See in-call reschedule validation for how the allowed hours are decided.

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Inbound calling

Inbound settings live inside the Calling tab. Toggle on Inbound Calling to assign an inbound number to this agent, match callers against a database, and set spam limits.

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Outbound call timing restrictions

Restrict outbound calls to a specific time window. This is off by default. Toggle it on to set an allowed calling window. The time window is validated against the recipient’s local timezone, detected automatically from their phone number. For example, a 9 AM start means 9 AM in the recipient’s timezone, not yours.

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Next steps