Voice Issues
Troubleshooting guide for voice-related problems.
Call Delivery Issues
Calls Not Connecting
| Issue | Solution |
|---|---|
| Insufficient voice minutes | Check your wallet and purchase more |
| SIP provider not configured | Verify organization settings |
| Invalid phone number | Check contact numbers for correct formatting (E.164 with country code) |
| Provider outage | Check your provider’s status page |
High Call Failure Rate
| Possible Cause | Solution |
|---|---|
| Invalid contact numbers | Clean your contact list — remove numbers with incorrect digit counts or invalid prefixes |
| Network congestion | Try calling during off-peak hours (early morning or late evening) |
| SIP credentials incorrect | Verify credentials in Settings — check username, password, and SIP server address |
| Concurrent call limit | Reduce concurrent calls in campaign settings — start with 5-10 and increase gradually |
⚠️ DND Hours & Compliance
Voice campaigns in India must respect DND (Do Not Disturb) regulations:
- Allowed hours: 9 AM to 9 PM IST for promotional calls
- DND registered numbers: Numbers on the NCPR (National Customer Preference Register) should not receive promotional calls
- Consequences: Calling DND numbers or calling outside allowed hours can result in your provider blocking your number, regulatory fines, and permanent account suspension
Always scrub your contact list against DND registries before launching campaigns. If your failure rate spikes during specific hours, verify your campaign schedule respects DND windows.
Audio Issues
Call Has No Audio
- Verify audio file is uploaded and valid in the Audio Library
- Test the audio file by playing it directly in the library
- Check that the correct audio is selected in the campaign configuration
- For TTS, verify the text is not empty and language/voice settings are supported
- For IVR, check that each node has audio or TTS configured
Poor Audio Quality
- Use higher bitrate audio files (MP3 at 128kbps or higher; WAV at 16-bit/8kHz for voice)
- Check the original recording quality — re-record if source audio has background noise
- Test with different audio files to isolate whether the issue is file-specific
- Audio files with extreme volume (too loud, too quiet) may distort on certain carriers
Call Quality Issues (Jitter, Latency, Packet Loss)
Call quality problems typically originate from the SIP provider side:
| Symptom | Possible Cause | Action |
|---|---|---|
| Choppy audio | Packet loss on SIP route | Contact your provider; test with a different provider |
| Delay/echo | High latency on the network path | Try calling numbers on different carriers to compare |
| Robotic voice | Audio codec mismatch | Verify codec settings in your provider configuration |
| Call drops mid-audio | Unstable SIP connection | Reduce concurrent calls; check provider server stability |
| One-way audio | NAT/firewall blocking RTP | Configure STUN/TURN if your provider supports it |
If call quality issues persist, run a test call to a known-good number (your own phone) and review the call log for duration and hangup cause codes. Share these with your SIP provider for diagnosis.
DTMF Detection Issues
If your IVR flow is not registering keypresses (DTMF tones):
- Timeout too short: Increase the gather node timeout setting. Default is typically 5 seconds; try 10 seconds for older phones or poor connections.
- Max digits mismatch: If you expect 1 digit (menu selection) but max digits is set higher, the system waits before processing. Match max digits to expected input length.
- Carrier DTMF mode: Some carriers use in-band DTMF while others use out-of-band (RFC 2833). If your provider uses in-band DTMF, detection reliability drops. Ask your provider about switching to RFC 2833.
- Test with multiple phones: Some phone models and VoIP apps do not reliably send DTMF tones. Test your IVR from different device types.
IVR Issues
IVR Flow Not Working
| Issue | Solution |
|---|---|
| Nodes not connected | Check node connections in the IVR builder — every node must have a path to an end state |
| Missing default route | Add a default route (no-input or invalid-input fallback) for unrecognized DTMF input |
| DTMF not detected | Check gather node settings (timeout, max digits, finish on key) |
| Infinite loop | Ensure every branch eventually reaches a hangup or transfer node |
Campaign Issues
Campaign Not Starting
- Verify voice minutes balance — campaigns fail silently if balance is zero
- Check campaign schedule settings — ensure the start time is not in the past and the end time is in the future
- Ensure contacts are selected — an empty contact list prevents launch
- Verify provider configuration in Organization Settings
- Check for conflicting campaigns — running too many campaigns simultaneously may exceed concurrent call limits
Campaign Performance Issues
- Monitor success rates — below 50% answer rate suggests contact quality issues
- Adjust calling hours — try B2B during 10 AM-12 PM and 3 PM-5 PM; B2C during 10 AM-1 PM and 4 PM-7 PM
- Review contact quality — remove invalid numbers after each campaign
- Segment contacts: if some regions or carriers show higher failure rates, contact those separately
Provider-Specific Issues
Different SIP providers have different characteristics:
| Provider Type | Common Issues |
|---|---|
| Indian Route (carrier-grade) | Subject to TRAI regulations and DND filtering. May block calls to certain number ranges. |
| International providers | Higher latency, variable quality. Check provider’s in-country presence. |
| Wholesale providers | Large capacity but may share routes with other traffic. Quality can fluctuate. |
If changing providers, verify the new credentials work with a small test campaign before migrating large-scale operations.