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Decibyl AI

Telephony Integration

Overview

Decibyl AI’s telephony integration system provides a unified interface for connecting with various telephony providers. The same configuration powers both outbound calls (initiated from Decibyl) and inbound calls (received on a phone number you own).

Supported Providers

Twilio

Industry-leading cloud communications platform with global reach

Vonage

High-quality voice with 16kHz audio and excellent international coverage

Plivo

Cloud communications platform with programmable voice and global PSTN reach

Cloudonix

SIP-based telephony with flexible trunk configuration

Vobiz

Cloud-based telephony with global reach and competitive pricing

Asterisk ARI

Connect to your own Asterisk PBX via the Asterisk REST Interface

Configuration

All telephony providers are configured from a single page in Decibyl:

  1. Navigate to /telephony-configurations and click Add configuration
  2. Select your provider
  3. Enter your credentials and save
  4. Open the new configuration and add at least one phone number
  5. (Optional) Assign an Inbound workflow to a phone number to enable inbound calling

A single org can hold multiple configurations (for example, separate Twilio sub-accounts) and multiple phone numbers per configuration. Mark one configuration as the default outbound to use it for test calls and campaigns by default.

Common Features

The telephony integration in Decibyl AI supports:

  • Outbound Calls: Initiate calls to any phone number from a workflow or campaign
  • Inbound Calls: Route incoming calls to the right voice agent — see the Inbound Calling guide
  • Call Transfer: Transfer an in-progress call to a human or another number (provider-dependent)
  • Call Status Tracking: Monitor call lifecycle events (initiated, ringing, answered, completed, failed)
  • WebSocket Audio Streaming: Real-time, bidirectional audio between caller and agent
  • Webhook Signature Verification: Inbound webhooks are verified against the matched configuration’s credentials

Inbound Calling

Inbound calls use a single org-wide webhook URL:

https://api.decibyl.ai/api/v1/telephony/inbound/run

Decibyl resolves the org from the webhook’s account credentials and the agent from the called number’s Inbound workflow assignment. See Inbound Calling for the full setup.

Troubleshooting

Calls not connecting
  • Verify credentials are correctly configured
  • Check phone number format (E.164 — the international standard: a +, then country code, then the number, no spaces or dashes, e.g. +1234567890)
  • Ensure webhook URLs are publicly accessible
  • Review provider-specific error logs
Audio quality issues
  • Check network bandwidth and latency
  • Verify audio codec compatibility
  • Review WebSocket connection stability
Webhook signature validation failing
  • Confirm auth tokens / API secrets match between provider and Decibyl configuration
  • Verify webhook URL matches exactly (including the /inbound/run path)
  • Check for proxy or load balancer modifications

Next Steps