title: Asterisk ARI create outbound call
body: <p>I'm trying to initiate calls using the ARI API, the process I followed was</p>
  
  <ol>
  <li>POST /ari/channels to create channel 1 to the local extension</li>
  <li>POST /ari/bridges to create a bridge</li>
  <li>POST /ari/bridges/{bridge-id}/addChannel with channel 1</li>
  <li>POST /ari/channels to create channel 2</li>
  <li>POST /ari/bridges/{bridge-id}/addChannel with channel 2</li>
  </ol>
  
  <p>I have a websocket connection waiting for the correct events (like channel status up) before calling the POSTs.</p>
  
  <p>The problem I'm having is this works using internal extension numbers for channel 1 and channel 2, but when using an external number for channel 2 I get the error - "Allocation failed".</p>
  
  <p>Any ideas where I'm going wrong...</p>