try

{
   "data":{
      "macaddress":{
            "00:6d:52:f1:f8:75":"iPad Air 2 di Massimiliano",
            "cc:32:e5:35:31:8b":"TAPO",
            "20:0d:b0:10:07:9b":"DevServer",
            "f8:54:b8:f8:0d:9f":"Alexa",
            "d8:0d:17:c4:e2:1e":"Ripetitore",
            "ac:bc:32:cc:d5:39":"MacBook Pro di Massimiliano",
            "c0:ee:fb:35:e0:9c":"OnePlus One",
            "10:13:31:fa:94:ee":"Modem"

      }
   }
}