Network Time Protocol
charter-ietf-ntp-03-00

Network Time Protocols working group

Good quality time is a key component of all modern systems, devices, and
applications. This quality time requires reliable and accurate network time
synchronization over modern IP-based networks. Additionally, accurate time
is fundamental to implementing many important security properties, and
therefore often must be (cryptographically, or otherwise) secured. The
Network Time Protocols working group is focused on enhancing existing
network time synchronization protocols, such as the Network Time Protocol
(NTP), and specifying new network time related protocols or extensions for
purposes which the existing protocols are not well suited to address.

NTP was first defined in the IETF in RFC 958 in 1985. It has been through
several iterations in the IETF. The latest, NTPv4 (RFC 5905) was published
in 2010. Today it is the most widely used time synchronization protocol for
the synchronization of clocks of various digital systems including
computers, networks, and a myriad of devices. Despite NTP's wide-spread
success it has become apparent that it needs further development in order
to adequately meet the modern requirements of time synchronization
protocols and to meet the increasing security threats of the Internet.

The working group will continue to to address the maintenance of NTPv4
including extensions and corrections. This includes the introduction of a
interleave mode in order to enhance the accuracy of the network time
synchronization and the introduction of alternative selection algorithms
in order to enhance robustness against delay attacks.

Despite its increasing importance, NTP remains vulnerable to many types of
attacks. Therefore, in 2020 the working group published Network Time
Security (NTS) as RFC 8915. NTS extends NTP with an authentication approach
to ensure authenticity of NTP time servers and protects the integrity of
exchanged NTP packets. The working group will work on extending NTS to
cover the remaining modes of service for NTP not covered by the initial
version. The working group will also work on extending NTS for PTP [1]
in collaboration with the IEEE 1588 working group.

The working group shall also develop an updated version of NTP
(preliminarily known as NTPv5), addressing a number of identified
weaknesses. The new specification shall comprise of a set of documents, in
order to distinguish between the on-wire protocol engine and the timing
engine of NTP clients and servers. The updated version of NTP will address
the security requirements specified in RFC 7384 and leverage the work
completed in RFC 8915.

Finally, the working group, will address other network time related
protocols in the IETF (e.g. roughtime) as well as work on items brought to
the group from other standards bodies (e.g. IEEE 1588), with the
acknowledged request to do so from that body.

Milestones:

• NTS for PTP
• NTPv5 requirements
• NTPv5 specificaition(s)
• roughtime specification

[1] PTP is the Precision Time Protocol as defined by the IEEE 1588. The
latest version is IEEE 1588-2019 - IEEE Standard for a Precision Clock
Synchronization Protocol for Networked Measurement and Control Systems.