[
   {
      "port":"/dev/ttyUSB0",
      "msisdn":"+393409821322",
      "imei":"990000862471854"
   },
   {
      "port":"/dev/ttyUSB1",
      "msisdn":"+443312123452",
      "pin": "12345"
   },
   {
      "port":"/dev/ttyUSB2",
      "msisdn":"+913446435634"
   },
   {
      "port":"/dev/ttyUSB3",
      "msisdn":"+12456345344"
   }
]