title: What does X-Backside-Transport Header do?
body: <p>I have come across this header for the first time and not sure what it does or mean. I have searched around and couldn't find what I was looking for.</p>
  
  <p>I am trying to consume a SOAP API using PHP SoapClient class and it's returning an empty response and these response headers. Also, no exception is thrown.</p>
  
  <pre><code>HTTP/1.1 200 OK
  X-Backside-Transport: FAIL FAIL,FAIL FAIL
  Connection: close
  Transfer-Encoding: chunked
  Content-Type: text/xml
  Date: Tue, 21 Jun 2016 20:09:50 GMT
  X-Client-IP: xx.xxx.xxx.xxx
  </code></pre>
  
  <p>Any help is appreciated.</p>