A call-rate limit controls how fast new call attempts can be launched. Concurrent channels limit how many calls can be up at the same time. Different customers stress them differently: an office PBX needs steady channels, an inbound operation needs headroom for peaks, and a predictive dialer launches bursts of attempts when a campaign list is fresh.
On a shared platform without per-customer limits, one customer's peak can consume capacity that belongs to everyone else. Per-account limits give each customer a guaranteed share, so an office PBX, an inbound queue and a dialer campaign can all run on the same network without affecting each other.
The right place to enforce limits is the session border controller, before traffic reaches the carrier. Per-account call-rate and simultaneous-channel limits mean each customer's burst is contained, and everyone else's traffic is unaffected.
Accounts get dedicated call-rate and simultaneous-channel capacity sized to their traffic, burstable on request. Limits are sized to your forecast and raised as you grow, and the acceptable-use policy is written with real traffic peaks in mind, so a busy day is expected and supported.
We onboard new customers on a prepaid model. Send the destinations you care about; we'll come back with rates and a test trunk.