How to measure Jitter

ksaad · ‎03-21-2004

I'm running two SAA probes to measure Jitter, whenever polling any jitter oid (SumRTT, etc) I'm getting two instances as seen below (3.346676620&

3.347036620 ) what are these instances.

host# snmpwalk -v2c -c Cisco 1.1.1.1 .iso.3.6.1.4.1.9.9.42.1.3.5.1.12.3

SNMPv2SMI::enterprises.9.9.42.1.3.5.1.12.3.346676620 = Counter32: 4914

SNMPv2SMI::enterprises.9.9.42.1.3.5.1.12.3.347036620 = Counter32: 4048

jsivulka · ‎03-26-2004

You could refer to the document "Measuring Delay, Jitter, and Packet Loss with Cisco IOS SAA and RTTMON" at http://www.cisco.com/en/US/tech/tk869/tk769/technologies_white_paper09186a00801b1a1e.shtml

ksaad · ‎03-26-2004

Thanks Jsivulka,

The document you mentioned is good but it does not answer my query what are those two values.

I have found out that the first value is the last hour

statistics and the second is the current hour statistics.

Thanks again for your reply.

grayd · ‎03-26-2004

You have two collections set up so each collection has an instance. You can issue the "sh rtr conf" on the router to determine which collector is which.

minie · ‎03-27-2004

To answer your question, we really need to get into how MIB works.

The object you are talking about belongs to rttMonJitterStatsEntry. This entry is indexed by two objects, rttMonCtrlAdminIndex and rttMonJitterStatsStartTimeIndex, which means every object in this entry will be indexed by above two.

rttMonJitterStatsEntry OBJECT-TYPE

SYNTAX RttMonJitterStatsEntry

MAX-ACCESS not-accessible

STATUS current

DESCRIPTION

"A list of objects which accumulate the results of a

series of RTT operations over a 60 minute time period.

This entry is created only if the rttMonCtrlAdminRttType

is jitter. The operation of this table is same as that of

rttMonStatsCaptureTable."

INDEX { rttMonCtrlAdminIndex, <--

rttMonJitterStatsStartTimeIndex <--

}

::= { rttMonJitterStatsTable 1 }

So enterprises.9.9.42.1.3.5.1 is rttMonJitterStatsEntry. enterprises.9.9.42.1.3.5.1.12 is rttMonJitterStatsNumOfPositivesSD. The 3 after 12 is the rttMonCtrlAdminIndex, and that big number at end, needless to say, is rttMonJitterStatsStartTimeIndex.

ftp://ftp.cisco.com/pub/mibs/v2/