The RMON history group is consists of two tables historyControlTable (control table )and the etherHistoryTable ( data table). firstly the historyControl table, as a control table is storing the configuration of sub network interface that will be monitored and the sampling periods ( intervals time ) and quantity of sampling needed each period and other parameters. Secondly the etherHistoryTable is data table consist of many column objects ,storing the values which are sampled in the sampling interval as we can see in RMON1 EtherStats .
The example in this slide on HistoryControlEntry table is history control table which highlighting the following parameters :
DataSource : is column object which Display the list of interfaces IP MIB (ports ) from which the history samples ( RMON information ) were taken.
Interval : is the time period of sampling from the interfaces (ports),which could be in Seconds or minuets. For example short –term interval can be 30 sec and long-term 30 min .Respectively the longer Interval period often highlight the higher abnormalities and lower priority of such sampling .
Buckets: BucketsRequested are number of how many sampling intervals requested , however the BucketsGranted refer to the available memory in the probe is garanted to store the BucketsRequested .Therefore BuketsRequested could be more than BucketsGranted due to the storage limitation in the prob.
Inaddition, this HistoryControlEntry has defined OwnerString ( owner info) and EntryStatus for arbitration and validation reasons, as it mentioned in previuse slides xxZL Sharing RMON tables and 1H.
Insummary, History control table enables the NM to creat a record of preformance of the network over the time as remote monitoring 06 Remote monitoring ,however that's consedered part of the performace management as mintioed in 8Y RMON in preformance managment and that will help the manager to troubleshoot in case of any malfunction of the network as part of Fault management as said in xx1H 07 Fault management .
Bruke.J, 2004, Network Management: concepts and practice, a hands-on approach, Pearson Education, pp. 208-224