CPS and channels are two different limits
CPS measures how fast you can originate new call attempts — how many INVITEs per second your trunk will accept. Channels (concurrent calls) measures how many calls, once connected, can be in progress at the same moment. A trunk can be capped on either independently: a high-CPS, low-channel trunk can dial fast but can't sustain many simultaneous conversations, and vice versa. Treating them as the same number is a common and costly mistake when sizing a predictive dialer.
Typical CPS tiers
| CPS | Roughly suited to |
|---|---|
| 1 CPS | A single small campaign or manual/preview dialing. |
| 5 CPS | A small predictive dialing campaign, a handful of agents. |
| 10 CPS | A mid-size call center campaign with moderate abandonment tolerance. |
| 25 CPS | A larger outbound floor or multiple concurrent campaigns. |
| 50+ CPS | Large-scale outbound/Press 1 broadcast operations. |
How the estimate below works
CPS is simply calls attempted ÷ the time window (in seconds) you attempt them over. The concurrent-channel estimate uses the standard queueing approximation (calls-per-second × average call duration, the same logic behind Little's Law) — it tells you roughly how many channels are occupied on average if attempts are spread evenly across the window, not a guarantee of your dialer's real peak, which also depends on pacing algorithm, answering-machine detection and abandonment settings.
Requesting higher capacity
If your calculated CPS or channel requirement exceeds what your current route supports, request a route test or request SIP credentials with your required CPS and concurrent-call figures — provisioning is never fabricated or auto-approved, an admin reviews real capacity before assigning it.