The IESG has approved the following document: - 'UDP Checksum Complement in the Network Time Protocol (NTP)' (draft-ietf-ntp-checksum-trailer-07.txt) as Experimental RFC This document is the product of the Network Time Protocol Working Group. The IESG contact persons are Brian Haberman and Terry Manderson. A URL of this Internet Draft is: https://datatracker.ietf.org/doc/draft-ietf-ntp-checksum-trailer/ Technical Summary: The Network Time Protocol (NTP) allows clients to synchronize to a time server using timestamped protocol messages. To facilitate accurate timestamping, some implementations use hardware-based timestamping engines that integrate the accurate transmission time into every outgoing NTP packet during transmission. Since these packets are transported over UDP, the UDP checksum field is then updated to reflect this modification. This document proposes an extension field that includes a 2-octet Checksum Complement, allowing timestamping engines to reflect the checksum modification in the last 2 octets of the packet rather than in the UDP checksum field. Working Group Summary: The document has clear working group consensus for publication, and has been reviewed by several WG participants since its initial adoption as a working group item. This document is similar to the â??UDP Checksum Complement in OWAMP and TWAMPâ?? (draft-ietf-ippm-checksum-trailer-05.txt) in the IPPM working group. The hardware aspects of the functionality described in this draft were implmented by Marvell. Document Quality: This document has been reviewed and revised several times during its development. There were no specific external expert reviews conducted. Personnel: Karen O'Donoghue is acting as the Document Shepherd. Brian Haberman is the Responsible Area Director.