title: Need help understanding the Firebase Storage CDN
body: <p>I'm building an audiobook app and have uploaded the audio files on Firebase Storage. My problem is that I experience different performances in San Francisco vs Toronto. I am under the impression that Firebase Storage has built-in CDN. if so, Do I need to enable it somewhere? if not, how do I add GCP CDN to my Firebase Storage files behind Firebase Auth??</p>
  
  <p>Checking the domain <code>storage.googleapis.com</code> which is where my Firebase Storage files are hosted shows that it is using the Google CDN. </p>
  
  <p>Here are the response headers for one of my public audio file request:</p>
  
  <pre><code>accept-ranges: bytes
  alt-svc: quic=":443"; ma=2592000; v="46,44,43,39"
  cache-control: public, max-age=3600
  content-disposition: inline; filename*=utf-8''G4PT7dPIyEuIz74BtTmm_FallIsTheLastSeasonOfTheYear.mp3
  content-length: 3162637
  content-type: audio/mp3
  date: Tue, 30 Apr 2019 17:13:34 GMT
  etag: "98013599e6f108a0edeeaac7c8b2bb45"
  expires: Tue, 30 Apr 2019 18:13:34 GMT
  last-modified: Mon, 08 Apr 2019 17:59:58 GMT
  server: UploadServer
  status: 200
  x-goog-generation: 1554746398034230
  x-goog-hash: crc32c=TKSAfA==, md5=mAE1mebxCKDt7qrHyLK7RQ==
  x-goog-meta-firebasestoragedownloadtokens: da578546-c265-4f06-ae11-6273a7812bf2
  x-goog-metageneration: 2
  x-goog-storage-class: STANDARD
  x-goog-stored-content-encoding: identity
  x-goog-stored-content-length: 3162637
  x-guploader-uploadid: AEnB2UqdvgzkJMC0yHJkGbr-K5cWWbXK5I2j6NLtd4NwG1G9swIhhp1QC8G25JUK4LItZID0IxuYhhLta3YImMTtzbKkr5vcEQ
  </code></pre>