Network Time Protocol Updated for Improved Granularity, IPv6

Internet Engineering Task Force (IETF) engineers are sharpening the Network Time Protocol's (NTP's) granularity of time measurements, as well as making the veritable time-synchronization standard compatible with version 6 of the Internet Protocol.

An IETF Internet Draft, "Network Time Protocol Version 4 Protocol and Algorithms Specification," which was posted last month, encapsulates the changes.

The NTP Working Group hopes to submit this draft for consideration as an IETF Request for Comments (RFC) within the next few weeks, according to working group Cochair Karen O'Donoghue, lead engineer for the Naval Sea Command's Surface Warfare Center. O'Donoghue led the working group discussion at the IETF 71st meeting being held in Philadelphia this week.

Once this update to NTP is published as an RFC, vendors can incorporate the changes into their own network software and hardware.

NTP is widely used to synchronize clocks across the Internet. Using NTP, local machines can query regional time servers, which in turn get the Universal Coordinated Time over the Internet from highly accurate reference clocks. Using algorithms to estimate the offset caused by transmission times, the current version of NTP can synchronize local time with a reference clock to within a few hundred milliseconds, an accuracy that may be maintained by checking the time server every 1,024 seconds.

This new NTP update includes algorithms that would bring the accuracy to within tens of milliseconds, and can maintain this accuracy up to 36 hours between checks with the time server. Such precision has become increasingly necessary for modern systems.

This draft also includes support for IPv6. It specifies the IPv6 address to be used for NTP multicast transmissions, as specified by Internet Assigned Numbers Authority. It also specified changes in the packet headers for IPv6 transmissions.

In addition to this draft, the NTP working group has a few others in the final stages of being readied for IETF submission. One is on using encrypting NTP packets through the Public Key Infrastructure. Another details how to use NTP with the Dynamic Host Control Protocol within IPv6. A third details metrics for monitoring components that use NTP.

The changes in this document will still fall under version 4 of NTP, although discussions are about to get underway to talk about future versions of the protocol, O'Donoghue said during the meeting.

About the Author

Joab Jackson is the chief technology editor of Government Computing News.