Network device having time correction function

A network device which is connected to a network, comprising:

• an internal clock;
• a time information obtaining section that obtains time information from a plurality of time servers on the network;
• and
• a time correcting section that corrects the internal clock based on the time information;
• wherein
• when a period of time between time information obtained from a first time server and time indicated by the internal clock is less than or equal to a predetermined period of time, the time correcting section corrects the internal clock based on the time information obtained from the first time server, and,
• when the period of time between the time information obtained from the first time server and the time indicated by the internal clock exceeds the predetermined period of time, the time correcting section corrects the internal clock based on time information obtained from a second time server only if a period of time between the time information obtained from the second time server and the time indicated by the internal clock is less than or equal to the predetermined period of time.

A method of correcting an internal clock which is built into a network device, the method comprising:

• obtaining time information from a time server on the network;
• and
• correcting the internal clock based on the time information;
• wherein
• when a period of time between the time information and time indicated by the internal clock is less than or equal to a predetermined period of time, the internal clock is corrected based on the time information;
• and
• when the period of time between the time information and the time indicated by the internal clock exceeds the predetermined period of time, the internal clock is corrected only if the internal clock has not been corrected.

A method of correcting an internal clock which is built into a network device, comprising:

• obtaining time information from a plurality of time servers on the network;
• and
• correcting the internal clock based on the time information;
• wherein
• when a period of time between time information obtained from a first time server and time indicated by the internal clock is less than or equal to a predetermined period of time, the internal clock is corrected based on the time information, and
• when the period of time between the time information obtained from the first time server and the time indicated by the internal clock exceeds the predetermined period of time, the internal clock is corrected based on time information obtained from a second time server only if a period of time between the time information obtained from the second time server and the time indicated by the internal clock is equal to or less than the predetermined period of time.

A storage medium readable by a computer, the storage medium storing a program of instructions executable by the computer having an internal clock to perform a function comprising:

• obtaining time information from a time server on the network;
• and
• correcting the internal clock based on the time information;
• wherein
• when a period of time between the time information and time indicated by the internal clock is less than or equal to a predetermined period of time, the internal clock is corrected based on the time information;
• and
• when the period of time between the time information and the time indicated by the internal clock exceeds the predetermined period of time, the internal clock is corrected only if the internal clock has not been corrected.

A storage medium readable by a computer, the storage medium storing a program of instructions executable by the computer having an internal clock to perform a function comprising:

• obtaining time information from a plurality of time servers on the network;
• and
• correcting the internal clock based on the time information;
• wherein
• when a period of time between time information obtained from a first time server and time indicated by the internal clock is less than or equal to a predetermined period of time, the internal clock is corrected based on the time information, and
• when the period of time between the time information and the time indicated by the internal clock exceeds the predetermined period of time, the internal clock is corrected based on time information obtained from a second time server only if a period of time between the time information obtained from the second time server and the time indicated by the internal clock is equal to or less than the predetermined period of time.

A network device which is connected to a network, comprising:

• an internal clock;
• a time information obtaining section that obtains time information from a time server on the network;
• a time correcting section that corrects the internal clock based on the time information;
• wherein
• when a period of time between the time information and time indicated by the internal clock is less than or equal to a predetermined period of time, the time correcting section corrects the internal clock based on the time information.