Network Monitoring (Probing) Two Devices - AudioCodes Mediant 800B MSBR User Manual

53.5

Network Monitoring (Probing) Two Devices

The device can be configured to monitor the quality of the network path (network quality
monitoring - NQM) between it and other AudioCodes devices. The path monitoring is done
by sending packets from a "sender" device to a "responder" device and then calculating the
round-trip time (RTT), packet loss (PL), and jitter. Since both responder and sender nodes
are AudioCodes devices, the monitoring is done by sending RTP/RTCP packets in a way
that accurately predicts the WAN service-level agreement (SLA) granted for real VoIP calls
by the network.
Note: If the packets sent mimic a G.711 or G.729 stream, the following quality
measurements are also done:
•
Listener quality MOS per ITU-T specification
•
Conversation quality MOS per ITU-T specification
You can configure up to 10 network quality probing paths. For example, you can configure
three probing paths, where your device is configured as a sender for three different
responder devices, as shown in the figure below:
You can periodically poll the device for the latest VoIP quality metrics and specify
thresholds for the quality metrics mentioned above. If these thresholds are crossed, the
device generates the following SNMP traps to Audiocodes EMS or third-party SNMP-based
manager:

NqmConnectivityAlarm: Connectivity with monitored probe destination is lost

NqmRttAlarm: High RTP detected toward probe destination

NqmJitterAlarm: High jitter detected toward probe destination

NqmPacketLossAlarm: High packet loss detected toward probe destination
User's Manual
Figure 53-5: Network Quality Probing Example
672
Mediant 800B MSBR
Document #: LTRT-12813