Re: [IPFIX] new monitoring interval information elements

Paul,

It depends on what kind of interval you want to specify.

If you want to specify the (re-)initialization time of the Metering 
Process, why not name the IE meteringProcessSysUpTime or (if you do not 
like sysup) meteringProcessInitializationTime?
And mention (re-)initialization in the description?
Dito for exportingProcessInitializationTime etc.

If we need the stop time, you can use meteringProcessStopTime or so.

If you want to define a new interval which is not starting at 
(re-)initialization time but later, then your definitions are ok. But 
this means that you need to specify new counter elements for this interval.

Thanks,
Gerhard


On 25.06.2012 19:08, Paul Aitken wrote:
> Gerhard,
>
>> Ok, I see the difference to discontinuity time.
>>
>> Some further thoughts:
>>
>> The common understanding is that the "time since re-initialization"
>> means sysUpTime. For example, have a look at the description of
>> flowEndSysUpTime:
>> "The relative timestamp of the last packet of this Flow. It indicates
>> the number of milliseconds since the last (re-)initialization of the
>> IPFIX Device (sysUpTime)."
>
> Yes, sysUpTime (so specifically, flowStartSysUpTime and
> flowEndSysUpTime), are times "since the last (re-)initialization of the
> IPFIX Device".
>
> These are not necessarily related to the metering process.
>
> Taking some other examples: octetTotalCount, packetTotalCount,
> droppedOctetTotalCount, droppedPacketTotalCount, observedFlowTotalCount,
> ignoredPacketTotalCount, ignoredOctetTotalCount,
> postMCastOctetTotalCount, ... are all of the form:
>
>       "The total number of X since the Metering Process
> (re-)initialization for this Observation Point."
>
> We could suppose that the Metering Process initialised at system uptime.
> However, that may not be the case: it could have started any amount of
> time later. eg, a user could configure a Metering Process at any time.
> Or, an automated system could start and stop Metering Processes
> according to different times of day or different network conditions.
> Without timestamps to tell us, we simply do not know.
>
>
>
>> Your proposed IEs do not mention neither (re-)initialization nor
>> sysUpTime. They rather seem to specify a time interval which is
>> located somewhere within the sysuptime interval. Hence, the interval
>> does not work to define the time frame of exportedMessageTotalCount,
>> for example. You would need to define a new IE
>> exportedMessageInMonitoringInterval.
>
> Indeed, because the IEs which I'm specifying here are particular to the
> Monitoring Process, whereas exportedMessageTotalCount seems to require a
> time reference for the Exporting Process. It's a related, though
> different, issue.
>
> (ie, the Exporting Process may start from system init, or at any time
> since then. It may have been started before, or after, the Metering
> Process. Without a suitable timestamp IE, we simply do not know.)
>
>
>> The different IE descriptions suggest that the time of
>> re-initialization (i.e. sysuptime) can be different for Metering
>> Process, Exporting Process etc.
>
> Indeed this is so. There is no necessity for these to be the same.
>
>
>> It seems that we need IE to export sysUpTime for each process.
>
> We agree.
>
> So in principal, you understand what I'm trying to do. However, you
> would like clearer definitions of the Information Elements?
>
> Thanks,
> P.
>



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