Hi team! We have been trying to launch our outbound campaigns and have tried 5–6 times, but the calls are not going through and are getting stuck after a few calls. What could be the reason? This is very important for our clients.

Thank you for reaching out. To help resolve your issue with launching outbound campaigns, could you please clarify what exactly happens when you try to start a campaign (e.g., do you see an error message, or do the calls not connect at all)? Sources: - [Outbound campaigns quickstart](https://docs.vapi.ai/outbound-campaigns/quickstart) - [Outbound campaigns overview](https://docs.vapi.ai/outbound-campaigns/overview)

The calls start, a few go out, and then it pauses with no more calls.

Your campaigns are likely pausing because you've reached the default concurrency limit (usually 10 simultaneous calls). To resolve this, increase your concurrency slots in the Vapi Dashboard: 1. Go to Settings → Billing → Reserved Concurrency (Call Lines). 2. Raise your limit or purchase additional call lines. This change takes effect immediately and will allow more calls to run in parallel. See more in the [Vapi concurrency documentation](https://docs.vapi.ai/calls/call-concurrency). Source: - [Call concurrency documentation](https://docs.vapi.ai/calls/call-concurrency)

What should be the setting if we are calling 1000 contacts?

Hi there, If your campaigns aren’t executing all calls as expected, the recommended workaround is to queue the calls as separate API calls instead of relying on a single large campaign run. This approach gives you more control over pacing and avoids concurrency limits. You can follow the same pattern shown in this example: