Network Time Protocol

E42445
network protocol time synchronization protocol

Network Time Protocol (NTP) is a widely used networking protocol designed to synchronize the clocks of computers and devices over packet-switched, variable-latency data networks.

Jump to: Surface forms Statements Referenced by

Observed surface forms (7)

Surface form Occurrences
NTPv4 2
NTP 1
NTPv1 1

Statements (55)

Predicate Object
instanceOf network protocol ⓘ
time synchronization protocol ⓘ
abbreviation NTP ⓘ
canUse GPS receivers as reference clocks ⓘ
atomic clocks as reference clocks ⓘ
radio clocks as reference clocks ⓘ
currentVersion Network Time Protocol self-linksurface differs ⓘ
surface form: NTPv4
defaultPort 123/UDP ⓘ
definedIn RFC 5905 ⓘ
defines stratum 0 reference clocks ⓘ
stratum 1 primary time servers ⓘ
stratum 2 secondary time servers ⓘ
designedBy David L. Mills ⓘ
epoch 1900-01-01 00:00:00 UTC ⓘ
firstSpecified 1985 ⓘ
handles variable-latency data networks ⓘ
hasAlternative IEEE 1588 Precision Time Protocol standard ⓘ
surface form: Precision Time Protocol

Network Time Protocol self-linksurface differs ⓘ
surface form: Simple Network Time Protocol
isUsedBy embedded systems ⓘ
network infrastructure devices ⓘ
operating systems ⓘ
servers ⓘ
layer application layer ⓘ
messageMode broadcast ⓘ
client-server ⓘ
manycast ⓘ
multicast ⓘ
symmetric active ⓘ
symmetric passive ⓘ
operatesOn packet-switched networks ⓘ
previouslyDefinedIn RFC 1305 ⓘ
purpose synchronize clocks of computers and devices ⓘ
securityExtension NTP Autokey ⓘ
Network Time Protocol self-linksurface differs ⓘ
surface form: NTS for NTP
standardizedBy Internet Engineering Task Force ⓘ
surface form: IETF
supports time synchronization over local area networks ⓘ
time synchronization over the Internet ⓘ
timeRepresentation 64-bit timestamp ⓘ
timeSource UTC ⓘ
timestampFormat 32 bits seconds and 32 bits fractional seconds ⓘ
typicalAccuracy better than one millisecond on local area networks ⓘ
within a few milliseconds over the public Internet ⓘ
uses Marzullo's algorithm ⓘ
UDP ⓘ
surface form: User Datagram Protocol

clock discipline algorithms ⓘ
clock filtering algorithms ⓘ
clock selection algorithms ⓘ
hierarchical system of time sources ⓘ
offset calculation between client and server ⓘ
round-trip delay measurement ⓘ
stratum model ⓘ
version Network Time Protocol self-linksurface differs ⓘ
surface form: NTPv1

Network Time Protocol self-linksurface differs ⓘ
surface form: NTPv2

Network Time Protocol self-linksurface differs ⓘ
surface form: NTPv3

Network Time Protocol self-linksurface differs ⓘ
surface form: NTPv4

Referenced by (10)

Full triples — surface form annotated when it differs from this entity's canonical label.

PTP → competesWith → Network Time Protocol ⓘ
Network Time Protocol → currentVersion → Network Time Protocol self-linksurface differs ⓘ
this entity surface form: NTPv4
Network Time Protocol → hasAlternative → Network Time Protocol self-linksurface differs ⓘ
this entity surface form: Simple Network Time Protocol
PTP → isMorePreciseThan → Network Time Protocol ⓘ
Network Time Protocol → securityExtension → Network Time Protocol self-linksurface differs ⓘ
this entity surface form: NTS for NTP
Cisco IOS → supportsProtocol → Network Time Protocol ⓘ
this entity surface form: NTP
Network Time Protocol → version → Network Time Protocol self-linksurface differs ⓘ
this entity surface form: NTPv1
Network Time Protocol → version → Network Time Protocol self-linksurface differs ⓘ
this entity surface form: NTPv2
Network Time Protocol → version → Network Time Protocol self-linksurface differs ⓘ
this entity surface form: NTPv3
Network Time Protocol → version → Network Time Protocol self-linksurface differs ⓘ
this entity surface form: NTPv4