Common issues and solutions for VoxPria SIP trunks. Find quick fixes for the most frequent problems you might encounter.

Quick Diagnostics #

System Status Check #

Before troubleshooting, verify system status:

1. Check VoxPria Status Page
2. Review your SIP provider’s status page
3. Verify your internet connection
4. Check call logs for error messages

Common Signs and Causes #

| Symptom | Likely Cause | Quick Fix |
|———|————–|———–|
| Import fails | Invalid format or rate limit | Check E.164 format, wait 1 minute |
| No inbound calls | Provisioning or routing issue | Verify trunk credentials, check status |
| Poor audio | Network or codec issue | Switch to TLS, test connection |
| Agent silent | Configuration problem | Check agent assignment and prompt |
| Webhook errors | Security misconfiguration | Verify webhook secret |

Phone Number Issues #

Phone Number Import Fails #

Symptoms:

• Import returns error message
• Number doesn’t appear in list
• “Invalid phone number” error

Solutions:
Check Number Format:

• Must use E.164 format: +[country code][number]
• ✓ Correct: +12125551234
• ✗ Wrong: 2125551234, +1-212-555-1234, (212) 555-1234

Verify API Configuration:
`bash

For ElevenLabs – Check API key #

Navigate to Settings → Integrations #

Ensure ElevenLabs API key is configured #

`
Check Rate Limits:

• Maximum 10 imports per minute
• If exceeded, wait 60 seconds
• Check response for rate limit headers

Confirm Provider Ownership:

• Number must exist in your provider account
• Verify number is active and not ported away
• Check provider dashboard for number status

Example Fix:
`bash

Instead of this #

curl -X POST /phone-numbers/import \

-d ‘{“phone_number”: “2125551234”}’ # Wrong format

Do this #

curl -X POST /phone-numbers/import \

-d ‘{“phone_number”: “+12125551234”}’ # Correct format

`

Provisioning Stuck or Failing #

Symptoms:

• Status shows “provisioning” indefinitely
• Provision button doesn’t work
• Error: “Provisioning failed”

Solutions:
For ElevenLabs Numbers:

1. Verify trunk credentials are correct
2. Check ElevenLabs dashboard shows number
3. Try deleting and re-importing
4. Ensure using sip.rtc.elevenlabs.io (not old address)
5. Verify plan includes SIP features

For OpenAI Numbers:

1. Provision at trunk level, not per-number
2. Verify OpenAI Project ID is correct
3. Check API key has Realtime permissions
4. Ensure webhook secret is configured
5. Provision entire project via trunk settings

Force Re-provision:

1. Edit the phone number
2. Click “Re-provision”
3. Wait 30 seconds
4. Refresh page to check status

Check Logs:
`bash

Via API – Check provisioning status #

curl -X GET /phone-numbers/{phone_id} \

-H “Authorization: Bearer YOUR_API_KEY”

Look for “status” and “error_message” fields #

`

Number Appears But Calls Don’t Connect #

Symptoms:

• Number imported and provisioned
• Status shows “active”
• Inbound calls don’t reach agent

Solutions:
Verify Agent Assignment:

1. Go to Phone Numbers list
2. Click Edit on your number
3. Confirm an agent is selected
4. Save if needed

Check SIP Routing:

1. Log into your SIP provider
2. Verify number routing points to correct destination
3. For ElevenLabs: Check termination settings
4. For OpenAI: Verify routing to OpenAI endpoints

Test With Provider:

1. Some providers have test numbers
2. Make test call through provider interface
3. Check provider’s call logs
4. Verify SIP registration

Connection and Audio Issues #

Inbound Calls Not Connecting #

Symptoms:

• Calls ring but never answer
• Immediate disconnect
• “Call failed” in logs

Solutions:
Verify Trunk Credentials:

1. Go to SIP Trunks
2. Edit your trunk
3. Verify username and password
4. Update if needed
5. Click “Re-provision All Numbers”

Check Transport Settings:

• Ensure transport matches provider requirement
• TLS (port 5061) recommended
• TCP (port 5060) as fallback
• Must match on both ends

For ElevenLabs:
`

Server: sip.rtc.elevenlabs.io

Port: 5061 (TLS) or 5060 (TCP)

Transport: TLS recommended

OLD ADDRESS (DON’T USE): sip.elevenlabs.io

`
For OpenAI:

1. Verify webhook URL is publicly accessible
2. Check webhook secret is configured
3. Test webhook with curl:

`bash

curl -X POST YOUR_WEBHOOK_URL \

-H “Content-Type: application/json” \

-d ‘{“test”: “data”}’

`
Check Firewall:

• Allow inbound SIP traffic (ports 5060-5061)
• Allow RTP media ports (typically 10000-20000)
• Check cloud provider security groups
• Verify no corporate firewall blocking

Outbound Calls Failing (ElevenLabs Only) #

Symptoms:

• Campaign calls don’t connect
• API calls return errors
• “Outbound not enabled” error

Solutions:
Enable Outbound:

1. Edit phone number in VoxPria
2. Check “Outbound Enabled” checkbox
3. Save changes

Verify Credits:

1. Log into ElevenLabs dashboard
2. Check account balance
3. Add credits if needed
4. Verify billing is current

Check Number Capabilities:

• Not all numbers support outbound
• Verify in ElevenLabs dashboard
• May need different number type

Test Single Call First:
`bash

Don’t start with campaigns #

Test single outbound call via API #

curl -X POST /calls/create \

-d ‘{

“from”: “+12125551234”,

“to”: “+13035559876”,

“agent_id”: “agent_abc123”

}’

`

Poor Audio Quality #

Symptoms:

• Choppy or robotic audio
• Echo or feedback
• Delayed responses
• Audio cuts out

Solutions:
Switch to TLS:

1. Edit your trunk
2. Change transport to TLS
3. Update port to 5061
4. Re-provision numbers
5. Test again

Check Codec Settings:

• VoxPria uses G.711 (default)
• Verify provider supports G.711
• Check for codec mismatches in logs

Test Network:
`bash

Check latency to SIP server #

ping sip.rtc.elevenlabs.io

Should be < 100ms for good quality #

> 200ms may cause issues #

`
Verify Bandwidth:

• Minimum: 100 Kbps per concurrent call
• Recommended: 200 Kbps per call
• Test from: fast.com or speedtest.net

Location Matters:

• Test from different locations
• Closer to provider = better quality
• Consider CDN or edge locations

Provider-Specific:

• Check provider’s network status
• Review provider’s best practices
• Contact provider support if persistent

Audio One-Way or Silent #

Symptoms:

• Caller can’t hear agent
• Agent can’t hear caller
• Complete silence

Solutions:
Check NAT/Firewall:

• Configure SIP ALG if available
• Open RTP port range (10000-20000)
• Use STUN/TURN if behind NAT

Verify Media Settings:

1. Check trunk configuration
2. Ensure media encryption matches provider
3. Verify SRTP settings if using TLS

Test From Different Network:

• Try from mobile data (bypass network)
• Test from different location
• Isolates network vs config issue

Agent and Webhook Issues #

Agent Not Responding #

Symptoms:

• Call connects but agent silent
• No greeting message
• Agent doesn’t interact

Solutions:
Verify Agent Configuration:

1. Check agent is assigned to number
2. Verify agent has system prompt
3. Test agent in VoxPria interface first
4. Check agent type (Natural for OpenAI)

Check First Message:
`bash

Ensure first message is configured #

{

“config”: {

“first_message”: “Hello! How can I help you today?”

}

}

`
Review Agent Logs:

1. Navigate to Call Logs
2. Find the call
3. Check for error messages
4. Look for agent initialization errors

For OpenAI Agents:

• Must be “Natural” type agent
• Structured/workflow agents won’t work
• Check agent type in agent settings

Test Agent Separately:

1. Use VoxPria’s web interface
2. Test conversation with agent
3. Verify responses work
4. Then test via phone

OpenAI Webhook Not Receiving Events #

Symptoms:

• Calls don’t trigger VoxPria
• No entries in call logs
• Webhook delivery logs show failures

Solutions:
Verify Webhook URL:
`

Should be: https://your-domain.com/api/v1/sip/openai/webhook

NOT: http:// (must use HTTPS)

NOT: localhost or 127.0.0.1

`
Check Webhook Secret:

1. Must match between OpenAI and VoxPria
2. Case-sensitive
3. No extra spaces when copying
4. Update in VoxPria trunk settings

Test Webhook Manually:
`bash

From OpenAI Platform #

curl -X POST YOUR_WEBHOOK_URL \

-H “X-OpenAI-Signature: test_signature” \

-d ‘{“event”: “call.started”}’

Should return 200 OK #

`
Verify SSL Certificate:
`bash

Check your domain’s SSL #

curl -v https://your-domain.com

Should show valid certificate #

No SSL errors #

`
Check Firewall:

• Allow HTTPS (443) inbound
• OpenAI’s IP ranges must be allowed
• No rate limiting on webhook endpoint

Review OpenAI Logs:

1. Go to OpenAI Platform
2. Check webhook delivery logs
3. Look for error messages
4. Note response codes

Webhook Signature Validation Failing #

Symptoms:

• HTTP 401 errors in webhook logs
• “Invalid signature” in VoxPria logs
• Events not processing

Solutions:
Update Webhook Secret:

1. Copy secret from OpenAI Platform
2. Edit OpenAI trunk in VoxPria
3. Paste secret exactly (no spaces)
4. Save changes
5. Re-provision project

Regenerate Secret:

1. In OpenAI Platform, regenerate secret
2. Update VoxPria immediately
3. Test with new secret

Verify Implementation:
`javascript

// Correct signature verification

const crypto = require(‘crypto’);

function verifySignature(payload, signature, secret) {

const hmac = crypto.createHmac(‘sha256’, secret);

const computed = hmac.update(payload).digest(‘hex’);

return crypto.timingSafeEqual(

Buffer.from(signature),

Buffer.from(computed)

);

}

`

Campaign Issues #

Campaign Calls Not Going Out #

Symptoms:

• Campaign shows “running” but no calls
• No entries in call logs
• Recipients not receiving calls

Solutions:
Check Number Requirements:

• Only works with ElevenLabs numbers
• Outbound must be enabled
• OpenAI numbers don’t support campaigns

Verify Campaign Configuration:

1. Check phone number is selected
2. Verify recipient list is uploaded
3. Ensure campaign is started (not paused)
4. Check scheduled time hasn’t passed

Review Recipient Format:
`json

// Correct format

[

{

“phone”: “+13035559876”,

“name”: “John Doe”

}

]

// Numbers must be E.164 format

`
Check Account Limits:

• Verify concurrent call limits
• Check ElevenLabs credit balance
• Review daily/monthly quotas

Test Single Call:

1. Try single outbound call first
2. Verify that works
3. Then try small campaign (5-10 calls)
4. Scale up gradually

High Campaign Failure Rate #

Symptoms:

• Many calls show “failed” status
• Low answer rate
• Frequent disconnects

Solutions:
Timing Optimization:

• Avoid early morning (before 9 AM)
• Avoid late evening (after 8 PM)
• Respect time zones
• Test different times

Number Reputation:

• New numbers may be flagged
• Build reputation gradually
• Start with low volume
• Increase over time

Check Recipient Numbers:

• Verify numbers are valid
• Remove disconnected numbers
• Check for typos in E.164 format
• Test with your own number first

Adjust Settings:
`json

{

“retry_failed”: true,

“retry_delay”: 3600,

“max_retries”: 2,

“call_timeout”: 30

}

`

Billing and Limits #

“Feature Not Available” Error #

Symptoms:

• Can’t create trunks
• Import limits restricted
• API returns 403 Forbidden

Solutions:
Verify Plan:

1. Check your VoxPria plan
2. Ensure SIP features included
3. Upgrade if necessary

Check Usage Limits:

• Free plans may have trunk limits
• Pro plans have higher limits
• Enterprise has custom limits

Contact Support:

• If features should be available
• Provide account details
• Request feature enablement

Rate Limit Exceeded #

Symptoms:

• HTTP 429 responses
• “Too many requests” errors
• Operations timing out

Solutions:
Respect Rate Limits:

• Phone imports: 10 per minute
• General API: 1000 per hour
• Implement exponential backoff

Implement Retry Logic:
`javascript

async function importWithBackoff(number, maxRetries = 3) {

for (let i = 0; i < maxRetries; i++) {

try {

return await importNumber(number);

} catch (error) {

if (error.status === 429) {

const delay = Math.pow(2, i) * 1000; // Exponential

await sleep(delay);

continue;

}

throw error;

}

}

}

`
Batch Operations:

• Use bulk import for multiple numbers
• Don’t loop rapid individual imports
• Space out API calls

Diagnostic Tools #

Test Your Configuration #

SIP Server Connectivity:
`bash

Test reachability #

nc -zv sip.rtc.elevenlabs.io 5061

Should show: Connection succeeded #

`
API Connectivity:
`bash

Test VoxPria API #

curl -I https://api.voxpria.com/v1/health

Should return: HTTP 200 OK #

`
Webhook Testing:
`bash

Test your webhook endpoint #

curl -X POST https://your-domain.com/webhook \

-H “Content-Type: application/json” \

-d ‘{“test”: “data”}’

Should return: 200 OK #

`

Logging and Monitoring #

Enable Detailed Logging:

1. Go to Settings → Developer
2. Enable debug logging
3. Reproduce issue
4. Download logs
5. Review for errors

Monitor Call Quality:

• Check call logs regularly
• Track success rates
• Monitor audio quality metrics
• Set up alerts for failures

Review Provider Logs:

• Most providers have call detail records
• Compare with VoxPria logs
• Identify where failures occur
• Cross-reference timestamps

Getting Help #

Before Contacting Support #

Gather this information:

1. Trunk Details:

• Trunk ID
• Provider type
• Creation date

1. Phone Number:

• Full number (E.164)
• Import date
• Current status

1. Call Details:

• Call ID
• Date and time
• Duration
• Error messages

1. What You’ve Tried:

• Steps already taken
• Results of each attempt
• Any error codes

1. Environment:

• VoxPria plan type
• SIP provider
• Network configuration

Support Channels #

VoxPria Support:

• Email: support@voxpria.com
• Dashboard: Help → Contact Support
• Community: community.voxpria.com

Provider Support:

• ElevenLabs: support@elevenlabs.io
• OpenAI: help.openai.com
• Your SIP provider’s support

Emergency Issues:

• Use “Urgent” priority
• Include impact assessment
• Provide call logs
• Note business impact

Common Error Codes #

SIP Error Codes #

| Code | Meaning | Solution |
|——|———|———-|
| 401 | Unauthorized | Check credentials |
| 403 | Forbidden | Verify permissions |
| 404 | Not Found | Check number exists |
| 408 | Timeout | Network/connectivity issue |
| 480 | Temp Unavailable | Retry later |
| 486 | Busy | Recipient busy, retry |
| 503 | Service Unavailable | Provider issue |

API Error Codes #

| Code | Meaning | Solution |
|——|———|———-|
| 400 | Bad Request | Check request format |
| 401 | Unauthorized | Verify API key |
| 403 | Forbidden | Check plan/permissions |
| 404 | Not Found | Resource doesn’t exist |
| 409 | Conflict | Resource already exists |
| 429 | Rate Limited | Slow down requests |
| 500 | Server Error | Contact support |

Preventive Measures #

Best Practices #

Regular Maintenance:

• Test trunks monthly
• Verify numbers weekly
• Update credentials regularly
• Monitor call quality metrics

Configuration Management:

• Document your setup
• Keep credential backup (secure)
• Note successful configurations
• Track changes

Monitoring:

• Set up alerts for failures
• Monitor success rates
• Track audio quality
• Review logs regularly

Testing:

• Test after any changes
• Use test numbers for new configs
• Validate before production
• Document test results

Avoiding Common Mistakes #

✗ Don’t:

• Skip webhook secret configuration
• Use old ElevenLabs server address
• Import numbers too quickly (rate limits)
• Forget to provision after import
• Use HTTP for production webhooks

✓ Do:

• Use TLS transport in production
• Configure webhook secrets immediately
• Respect rate limits
• Test thoroughly before going live
• Keep credentials secure

Next Steps #

• Review Security Best Practices for production hardening
• Check API Reference for automation options
• Visit FAQ for additional questions
• Join Community Forum for tips

Still having issues? Contact VoxPria support with your diagnostic information for personalized help.