{
  "method": "INVITE",
  "uri": "sip:user@example.com",
  "version": "2.0",
  "headers": {
    "contact": [
      {
        "uri": "sip:caller@host5.example.net",
        "params": {}
      }
    ],
    "to": {
      "uri": "sip:j.user@example.com",
      "params": {}
    },
    "from": {
      "uri": "sip:caller@example.net",
      "params": {
        "tag": "8392034"
      }
    },
    "max-forwards": "70",
    "call-id": "invut.0ha0isndaksdjadsfij34n23d",
    "via": [
      {
        "version": "2.0",
        "protocol": "UDP",
        "host": "somehost.example.com",
        "params": {
          "branch": "z9hG4bKkdjuw"
        }
      }
    ],
    "content-type": "application/unknownformat",
    "content-length": 40
  },
  "content": "<audio>\r\n <pcmu port=\"443\"/>\r\n</audio>\r\n"
}