The present invention is generally directed to a method of correcting time data when collecting performance data in a network management application using a Simple Network Management Protocol (SNMP), and more particularly to a method of enabling the application to collect more accurate performance data by correcting possible errors of the time data when collecting the performance data.
The SNMP is a standard network management protocol for managing various kinds of Internet devices and was established as the first standard by International Engineering Task Force (IETF) in 1990. In an application using the SNMP, the application keeps statistical data from reply data, which is requested to statistic items periodically in order to collect statistical data. As a result of such information request, the reply data is stored along with the time data and can be used to evaluate the performance. However, the error of the time data can occur due to the delay of a network or a time tick of a device during the procedure of requesting periodical information.
The primary objective of the present invention is to provide a method of correcting time data in a network management application so as to keep the performance information in a more precise manner.
The present invention provides a method for achieving the above objective, which comprises the following steps:
waiting for 90% of a polling period after requesting performance information and statistic information;
checking time data every 500 ms after the 90% of the polling period; and
requesting the performance information and the statistic information when information requesting time is reached.
In view of the provided figures, a preferred embodiment of the present invention, which is in accordance with the subject matter disclosed above, will be described in detail.
The above method of collecting the performance information and the statistic information is described below. The method comprises the following steps:
waiting for 90% of a polling period after requesting performance information and statistic information;
checking time data every 500 ms after the 90% of the polling period; and
requesting the performance information and the statistic information when reaching information requesting time.
With the above method, the error of the time data decreases remarkably compared to when using the conventional method. In the conventional method, the time data of Nth, information requesting time can be obtained as follows.
D=(T+D1+D2)*N Equation 1
D: time data of Nth information requesting time
T: polling period
D1: time tick delay of device
D2: time delay of network
N number of requesting information
The value of (D1+D2)*N (i.e., D−T*N) is the error of time data and the error increases as N increases. However, the time data of Nth information requesting time according to the method of the present invention can be obtained as follows.
D=T*N+D1+D2 Equation 2
D: time data of Nth information requesting time
T: polling period
D1: time tick delay of device
D2: time delay of network
N: number of requesting information
In the above equation, the value of D−T*N equals to that of D1+D2, and the value is constant regardless of N. Therefore, if D1 and D2 are predictable, it is possible to keep the time data precise to some extent. Moreover, unless the values of D1 and D2 are accumulated, the variations of D1 and D2 would not affect the time data since the amount of an instantaneous error, such as a casual network delay or a time tick delay of a device, is so small that it can be neglected. In other words, when comparing equation 1 and equation 2, it will be appreciated that although the error of the time data increases in proportion to N with equation 1, the time data can be precisely kept in equation 2. This is because the error is affected only by the determined values, which is independent of N.
Therefore, the method of correcting the time data in a network management application using a SNMP in accordance with the present invention enables to keep the time data exact and to change the period of requesting information based on the above exact time data.
The method of correcting time data in a network management application using a SNMP in accordance with the present invention provides the benefits in that the increase of delay time can be resolved. That is, although there exists a possibility that the management application cannot work due to the increasing delay time, which is originated from the polling scheme in the conventional application using a SNMP, the method of the present invention removes the above possibility by continuously monitoring the time of requesting information.
Number | Date | Country | Kind |
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10-2004-0002979 | Jan 2004 | KR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/KR05/00138 | 1/14/2005 | WO | 6/4/2007 |