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Overview

Inbound Voice connections simulate users calling your agent through traditional telephony.

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Configuration Requirements

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Phone Number

  • Field: phone_number
  • Type: String (required)
  • Format: E.164 international format with country code, or a SIP address
  • Examples: +12345678901, sip:agent@example.com
  • Validation: Must be a valid phone number or SIP URI

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Wideband Audio

When your agent is configured with a SIP address, a Wideband Audio (16kHz) toggle appears in the agent configuration page. Enabling this toggle switches the audio encoding from the default narrowband codec (G.711 mu-law at 8kHz) to wideband L16 PCM at 16kHz, providing higher quality audio.

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When to use wideband audio

Wideband audio is beneficial when your agent uses a SIP address (e.g., sip:agent@example.com) and supports a wideband codec. In this configuration the audio is 16kHz end-to-end, giving a meaningful quality improvement. This toggle only appears for SIP connections because PSTN phone numbers are limited to narrowband audio (8kHz G.711) on the carrier leg. Even if wideband encoding were used on the Coval side, the PSTN leg would still be narrowband, so there is no actual quality benefit.

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How to enable it

  1. In the agent configuration page, select a SIP address as your connection type
  2. A Wideband Audio (16kHz) toggle will appear
  3. Enable the toggle to use wideband audio
When the wideband toggle is off (the default), standard narrowband PCMU encoding is used. Existing agents are unaffected unless you explicitly enable wideband audio. Note that some PSTN carriers may transcode audio, which can reduce quality regardless of the codec setting.

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Setup Instructions

  1. Select “Inbound Voice” as the connection type
  2. Enter your agent’s phone number in E.164 format or SIP address
  3. (Optional) If using a SIP address, enable the Wideband Audio (16kHz) toggle for higher quality audio
  4. Save and test the configuration

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Technical Details

Call Flow
  1. Coval initiates call to configured phone number
  2. Your agent answers and begins conversation
  3. Audio processed in real-time
  4. Session continues until completion or timeout

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Troubleshooting

Common Issues:
  • Invalid Phone Number Format: Ensure E.164 format with country code
  • Call Connection Failures: Verify number is active and accessible
  • Poor Audio Quality: Check telephony provider settings. For SIP agents, consider enabling the Wideband Audio (16kHz) toggle
  • Timeout Issues: Adjust agent response timing configuration