By default, all accounts come with 2 calls per second per account. Outbound Call API requests are queued upon acceptance, then dequeued and initiated as per the Calls Per Second (CPS) configured for your Plivo account.     

For example, if your Account CPS is 10 Calls Per Second, but 15 Make Call API requests are received in one second, the first 10 calls would be dequeued and processed instantly. The remaining 5 calls would be dequeued and processed with a delay of one second. 


The Make Call API will respond with the following Response body. 

"message": "call queued",
"request_uuid": "9834029e-58b6-11e1-b8b7-a5bd0e4e126f", 
"api_id": "97ceeb52-58b6-11e1-86da-77300b68f8bb"

Please note the change in the value of the ‘message’ response param from ‘call fired’ to ‘call queued’.

Please note that this only applies to outbound calls initiated via the Make Call API. Outbound calls initiated via the Dial XML will not see any change.

Managing Queued Calls     


Plivo Voice API provides rich functionality to manage queued calls. 

The Retrieve Queued Calls API provides visibility into your outbound call queue. 

Queued calls may be canceled and removed from the queue using the Hangup Call API