{"draft":"draft-ietf-ippm-checksum-trailer-06","doc_id":"RFC7820","title":"UDP Checksum Complement in the One-Way Active Measurement Protocol (OWAMP) and Two-Way Active Measurement Protocol (TWAMP)","authors":["T. Mizrahi"],"format":["ASCII","HTML"],"page_count":"15","pub_status":"EXPERIMENTAL","status":"EXPERIMENTAL","source":"IP Performance Measurement","abstract":"The One-Way Active Measurement Protocol (OWAMP) and the Two-Way\r\nActive Measurement Protocol (TWAMP) are used for performance\r\nmonitoring in IP networks.  Delay measurement is performed in these\r\nprotocols by using timestamped test packets.  Some implementations use\r\nhardware-based timestamping engines that integrate the accurate\r\ntransmission time into every outgoing OWAMP\/TWAMP test packet during\r\ntransmission.  Since these packets are transported over UDP, the UDP\r\nChecksum field is then updated to reflect this modification.  This\r\ndocument proposes to use the last 2 octets of every test packet as a\r\nChecksum Complement, allowing timestamping engines to reflect the\r\nchecksum modification in the last 2 octets rather than in the UDP\r\nChecksum field.  The behavior defined in this document is completely\r\ninteroperable with existing OWAMP\/TWAMP implementations.","pub_date":"March 2016","keywords":["Checksum","UDP","IPPM","timestamping"],"obsoletes":[],"obsoleted_by":[],"updates":[],"updated_by":[],"see_also":[],"doi":"10.17487\/RFC7820","errata_url":null}