Concurrent calls

Concurrent calls are the number of conversations that can run at the same time on a phone line, a PBX or a call platform. A business may have a single phone number, but how many calls can reach that number at once is a separate question. When capacity is full, a new caller hears a busy tone or is placed in a queue. It is one of the basic planning questions for both inbound and outbound calling.

How it works

Several layers limit concurrency together. The number of channels on the SIP trunk from your carrier determines how many calls can be carried at once. The licence and server capacity of the PBX or call center software is the second limit. Where people answer the phone, the real limit is how many operators are free at that moment; extra calls wait in the call queue. With an AI voice agent, each conversation runs as its own session, so the agent can answer several calls at the same time.

Why it matters

Plan capacity for the busiest hour, not the average: on campaign days, before public holidays or on Monday mornings, calls arrive on top of each other. On outbound calls, concurrency is limited on purpose; dialling too many people at once leaves customers waiting on the line when there is no operator free to take the call.