How does Exotel integration work with Vtiger?

Following is a simplified workflow of Exotel calls in Vtiger CRM:

1. Adding members - CRM admins must then add their sales and support representatives as co-workers in Exotel, along with their phone numbers.
2. Setting up phone numbers - Individual sales and support representatives must set up their phone number (the same number in Step 2) as their Exotel Extension Number in the CRM preferences. 
3. Incoming calls - When a customer calls on the Exotel Number, the call is routed to the sales and support representatives, who are added as co-workers. Any one of the representatives can attend the call.
4. Outgoing calls - When a sales and support representative calls a customer, the call is first routed to the representative’s own extension number. They must first receive the call on their extension number, after which the call connects to the customer.