3Com MSR 50 Series Configuration Manual page 2052

2052 C 111: NTP C
HAPTER ONFIGURATION
Figure 611 Clock synchronization message format
0 1 4
LI VN Mode
Main fields are described as follows:
LI: 2-bit leap indicator. When set to 11, it warns of an alarm condition (clock
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unsynchronized); when set to any other value, it is not to be processed by NTP.
VN: 3-bit version number, indicating the version of NTP. The latest version is
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version 3.
Mode: a 3-bit code indicating the work mode of NTP. This field can be set to
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these values: 0 - reserved; 1 - symmetric active; 2 - symmetric passive; 3 - client;
4 - server; 5 - broadcast or multicast; 6 - NTP control message; 7 - reserved for
private use.
Stratum: an 8-bit integer indicating the stratum level of the local clock, with
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the value ranging from 1 to 16. The clock precision decreases from stratum 1
through stratum 16. A stratum 1 clock has the highest precision, and a stratum
16 clock is not synchronized and cannot be used as a reference clock.
Poll: 8-bit signed integer indicating the poll interval, namely the maximum
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interval between successive messages.
Precision: an 8-bit signed integer indicating the precision of the local clock.
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Root Delay: roundtrip delay to the primary reference source.
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Root Dispersion: the maximum error of the local clock relative to the primary
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reference source.
Reference Identifier: Identifier of the particular reference source.
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Reference Timestamp: the local time at which the local clock was last set or
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corrected.
Originate Timestamp: the local time at which the request departed the client
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for the service host.
7 15
Stratum
Root delay (32 bits)
Root dispersion (32 bits)
Reference identifier (32 bits)
Reference timestamp (64 bits)
Originate timestamp (64 bits)
Receive timestamp (64 bits)
Transmit timestamp (64 bits)
Authenticator (optional 96 bits)
23
Poll Precision
31