npm install
npm start

List all phones

GET: /phones

Register a new phone

POST: /phones

Get all connections

GET: /connections

Create a new connection

POST: /connections

Content-Type: application/json

{
  "caller": 9xxxxxxxxx,
  "callee": 9xxxxxxxxx
}

Get connection

GET: /connections/:connectionID

Update connection

POST: /connections/:connectionID/:action

action = call, ring, accept, reject, cancel, close, ignore