MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="MIME_boundary-1"; type="text/xml";
Content-Description: Some_description

--MIME_boundary-1
Content-Type: text/xml; charset="UTF-8"
Content-Transfer-Encoding: 8bit
Content-Location: dataHeader.xml
<?xml version="1.0" encoding="UTF-8"?>
<Header>
 <DataLen>123456</DataLen>
</Header>

--MIME_boundary-2
Content-Type: application/octet-stream
Content-Location: data.bin
1828323232
--MIME_boundary-2