iOS devices and itunes server on NAS

I cannot play music on my iOS devices connecting to iTunes Server on my WD Cloud NAS.

-WD My Cloud gen2

  • Same WiFi SSID
    -all music on WD Cloud in Shared Music directory
    -When using laptop with iTunes software connected to My Cloud music plays
  • When laptop is off, iOS device cannot connect to iTunes Server and play music.

What is wrong?