<record>
  <controlfield tag="001">124</controlfield>
  <datafield tag="653" ind1="1" ind2=" ">
    <subfield code="a">IEEE 1588</subfield>
  </datafield>
  <datafield tag="653" ind1="1" ind2=" ">
    <subfield code="a">Precise Time Protocol</subfield>
  </datafield>
  <datafield tag="653" ind1="1" ind2=" ">
    <subfield code="a">Network Time Protocol</subfield>
  </datafield>
  <datafield tag="653" ind1="1" ind2=" ">
    <subfield code="a">security analysis</subfield>
  </datafield>
  <datafield tag="653" ind1="1" ind2=" ">
    <subfield code="a">time synchronization</subfield>
  </datafield>
  <datafield tag="653" ind1="1" ind2=" ">
    <subfield code="a">network security</subfield>
  </datafield>
</record>