Quick start with a preset scenario:
Input Parameters
Connected Calls
25,000
Unanswered Calls
75,000
Calling Window
43,200s
Total Call Time
2,475,000s
Capacity Requirements
Calls Per Second (CPS)
Rate of new call initiation
Concurrency (Simultaneous)
Active calls at any moment
Calls Per Minute
Useful for provider rate limits
Recommendations
- Ensure your SIP trunk supports at least 69 concurrent channels.
- Set up monitoring for CPS throttling — your provider may rate-limit above 2.8 CPS.
- Consider distributing calls across multiple origination points for redundancy.
- Always test with a small batch before launching a full campaign.
- Monitor real-time CPS and concurrency dashboards during live runs.
Understanding the Metrics
Calls Per Second (CPS)
CPS represents the rate at which your system initiates new call requests. High CPS requires robust signaling infrastructure. If your CPS matches or exceeds your account limit, calls may be throttled or rejected.
Concurrency
Concurrency measures calls active at any single moment — both ringing and connected. Higher concurrency requires more active channels and media processing capacity from your telephony provider.
How the Math Works
CPS Formula
Distributes your total daily volume evenly across the calling window.
Concurrency Formula
Accounts for the holding time of both successful and failed call attempts.
Best Practices
Monitor peak hour traffic — it usually exceeds the daily average by 1.5×.
Increase ring time if you notice low pickup rates to allow more answering time.
Ensure your SIP trunk configuration matches your maximum concurrency needs.
Use short ring times for high-volume automated dialers to clear channels faster.
Test with a small batch before launching full-scale campaigns.
Set up real-time alerting for CPS and concurrency thresholds.
