Rate limits for the Voice API are set by account by your customer account manager. By default, rate limits are set to 3 CPS and 30 active sessions. If you think you may need additional voice capacity, please open a ticket with our Account Management team.
If a rate limit is hit when creating an outbound call the API will return a
HTTP-429. If a rate limit is hit during a
<Forward>, the error will be sent in to the
disconnectUrl. If a rate limit is hit during a
<Transfer>, the error will be sent to
transferCompleteUrl. There are no notifications when inbound calls are rejected due to rate limits.