NTP in the Internet
Used for research, services, air
traffic control, stock trading, and
many corporate networks
Public NTP servers operated by
national
standards
labs
worldwide
NTP Protocol Versions
NTPv3 is the official standard
specified in RFC 1305
NTPv4 extends NTPv3 but has
no single defining specification
yet
SNTPv4 is a compatible subset
for simple clients and servers
Importance of Common Algorithms
Early NTP specs
architecture
implementation
separated
from
But Internet NTP servers are
now a tightly coupled system
So common algorithms are
needed for stability, especially
for clock discipline
NTPv4
reference
implementation
contains
carefully engineered algorithms
These algorithms likely need to
be standardized going forward
Widespread Adoption
NTPv4
reference
implementation is a product of
many years of volunteer work
Compatible with but extends
previous versions
NTP is likely the
continuously running
application protocol
Widely deployed on hosts and
routers across the Internet
longest
Internet
Availability
NTPv4
reference
implementation
and
docs
available for free at ntp.org
Ported to many architectures
from PCs to supercomputers
Build process is automated and
requires
minimal
system
configuration
Online
resources
include
technical articles, news, and
discussion forums
Highlights
NTPv3 is the official standard
but NTPv4 widely used in
practice
NTP algorithms are crucial for
stability in the Internet
Widespread adoption for critical
functions like finance and air
traffic control
NTPv4
reference
implementation available and
runs on most architectures
Global infrastructure of public
servers plus many private
deployments