Platform
A phone number is what turns an agent from something you talk to in the dashboard into something a real caller can dial. Numbers and the accounts behind them are configured under Configurations → Integrations; which one an agent uses is set on that agent's own Telephony tab.
Sonex places and receives calls through one of three telephony providers. Which one to use is mostly a matter of where your callers are: Twilio and Vobiz cover international numbers, Exotel is built for Indian numbers and carries India-specific features like DTMF and a configurable ring timeout. An agent is not locked to one provider platform-wide — different agents can use different providers, each configured as its own integration.
The fastest way to get a working number is one Sonex already owns and has configured — pick it on an agent's Telephony tab and there is nothing else to set up. This is the right choice for testing an agent or for a low-volume line where owning your own carrier account is not worth the overhead.
To use a number you already own, add its account under Configurations → Integrations: select Add integration, choose the provider, and enter its credentials (an Account SID and Auth Token for Twilio; an API Key, API Token and Account SID for Exotel; an Auth ID and Auth Token for Vobiz). Once saved, that account's numbers become selectable on any agent's Telephony tab, the same way a Sonex-provided number is.
On the agent's Telephony tab, set Direction to Inbound, then choose the telephony account and the phone number this agent should answer on. From the moment that is saved, a call to that number reaches this agent — there is nothing further to wire up on the provider's own side.
Set Direction to Outbound and choose the account and number to place calls from. A single call can be triggered from an agent's Sandbox tab (see Ring your own phone) or through the API; calling a list of contacts at scale is a Campaign, started from the Campaigns page in the sidebar rather than from an individual agent.
On a Sonex-provided number, the carrier leg is billed in whichever block the provider itself bills in — 30-second increments on Exotel, 60-second increments on Twilio and Vobiz — rounded up, the same way the underlying carrier rounds up to us. A 31-second Exotel call is billed as 60 seconds; a 61-second Twilio call is billed as 120. On a BYO account there is no platform charge for the call leg at all, since the carrier is already billing you directly.
This is separate from the language model, voice and transcription charges the same call also carries — see How each service is billed for the full breakdown.