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Chapter 3: Supported Reports and KPIs
42 IBM Tivoli Netcool/Proviso Cisco IP Telephony 2.4.0.0 Technology Pack
MOS Mean Opinion Score. This is an high level metric. Note: There is no
algorithm for Mean Opinion Score calculations. This is a subjective metric
from the end user point of view. In voice communications, particularly
Internet telephony, the mean opinion score (MOS) provides a numerical
measure of the quality of human speech at the destination end of the circuit.
The scheme uses subjective tests (opinionated scores) that are
mathematically averaged to obtain a quantitative indicator of the system
performance. To determine MOS, a number of listeners rate the quality of
test sentences read aloud over the communications circuit by male and
female speakers. A listener gives each sentence a rating as follows: - 1 bad; -
2 poor; - 3 fair; - 4 good; - 5 excellent. The MOS is the arithmetic mean of
all the individual scores, and can range from 1 (worst) to 5 (best). In our
context, our MOS calculation is based on the consolidation of Jitter, Latency
and Packets Lost values which give us a good overview of the real MOS
value.
NbPacketsLost Number of Packets Lost by the subelement during a call. This metric comes
from the CMR table. Its set only once the call is established. This metric is
only available for IP Phones.
NbPacketsReceived Number of Packets Received by the subelement during a call. This metric
comes from the CMR table. Its set only once the call is established. This
metric is only available for IP Phones.
NbPacketsSent Number of Packets Sent by the subelement during a call. This metric comes
from the CMR table. Its set only once the call is established. This metric is
only available for IP Phones.
OffNet Identifies a call where at least one PSTN Gateway is involved in the Voice
path, with the following criteria: - Inbound or Outbound call - Internal or
call to/from PSTN number - Intersite or Intrasite Legacy PBX Call
OnNet Identifies a call where the caller is an internal extension and where the callee
is also an internal extension, from the same site or different sites, with the
following criteria: - Outbound call - Internal call - Intersite or Intrasite IP
Call - No PSTN Gateway is involved in the Voice path - This is a pure IP to
IP call
Outbound Loss (percent) Out of all outbound traffic to be sent by this entity, the percentage of PDUs
that: (a) contained defects which prevented them from being transferable, or
(b) were discarded even though no errors are detected (i.e. due to congestion
or resource limitations).
PSTN Gateway Active DS0 Channels (Nb) Total number of active DS0 channels for all of the enabled PRIs in a PSTN
device
PSTN Gateway Active DS0 Channels (Nb)
(Gauge) Total number of currently active DS0 channels for a PSTN gateway
PSTN Gateway Call Setup Quality (percent)
(Successful / Total) Percentage of successful call setups for a PSTN gateway device
PSTN Gateway DS1 Active DS0 Channels
(Nb) Number of Active DS0s Channel that are active for a specific Serial E1/T1
Interface. Because there is no specific OID for thisin the MIB we assume
that: 1 Call = 1 DS0 Channel = 64 kbpsThenThroughput (in or out) /
64000 = Active Channels
Table 2: Key performance indicators
KPI Comment