Quadro4Li Manual II: Administrator's Guide
Administrator’s Menus
Quadro4Li; (SW Version 5.3.x)
72
To Reset the Statistics
1.
Press the
Clear All Records
button in the
Call Statistics Settings
page.
2.
Confirm the deletion by clicking on
Yes
. The call statistics will then be deleted. To abort the deletion and keep the statistics information,
click on
No
.
RTP Statistics
The
RTP Statistics
page provides detailed information about the established call is provided. When Quadro serves as an RTP proxy, this page
displays two groups (legs) of RTP statistics. For example, when calling from an IP Phone attached to the Quadro’s IP line to an external SIP
destination or from one external SIP destination to another through the Quadro’s Auto Attendant. Each group of parameters describes characteristics
of a piece of RTP stream composing an overall SIP session. Normally, one leg describes the RTP stream from caller to the Quadro and the other leg
describes the RTP stream from Quadro to the destination.
Quality
- estimated call quality, which depends on RTP statistic.
Below is the legend for Call Quality definitions on the displayed RTP
Statistics:
excellent
– RX Lost Packets < 1% & RX Jitter < 20
good
- RX Lost Packets < 5% & RX Jitter < 80
satisfactory
- RX Lost Packets < 10% & RX Jitter < 150
bad
- RX Lost Packets < 20% & RX Jitter < 200
very
bad
- RX Lost Packets > 20% or RX Jitter > 200
The
Source
and
Destination
fields indicate the two peers between
which the RTP stream is transmitted. The characteristics in the table
below describes to the piece of RTP stream between these peers.
Rx/Tx Codec
- codec for received and transmitted RTP stream
respectively.
Rx/Tx Packets
- number of RTP packets received and
transmitted respectively.
Rx/Tx Packet Size
- size of RTP packet (payload) received and
transmitted respectively.
Rx Lost Packets
- number of lost RTP packets for received stream.
Rx Jitter
- inter-arrival jitter is an estimate of the statistical variance
of the RTP data packet inter-arrival time, measured in timestamp
units.
Fig. II-126: RTP Statistics page
The inter-arrival jitter is defined to be the mean deviation (smoothed absolute value) of the difference D in packet spacing at the receiver compared
to the sender for a pair of packets. If Si is the RTP timestamp from packet i, and Ri is the time of arrival in RTP timestamp units for packet i, then for
two packets i and j, D may be expressed as:
D(i,j) = (Rj - Ri) - (Sj - Si) = (Rj - Sj) - (Ri - Si)
J(i) = J(i-1) + (|D(i-1,i)| - J(i-1))/16, where J(i) is Rx Jitter for packet i.
For more details about Jitter calculations, please refer to the RFC1889.
Rx Maximum Delay
- maximum variance (absolute value) of actual arrival time of the RTP data packet compared to estimated arrival time,
measured in milliseconds.
If Si is the RTP timestamp from packet i, and Ri is the time of arrival in RTP timestamp units for packet i, then variance for packet i may be
expressed as following: V(i) = |(Ri - R1) - (Si - S1)| = |(Ri - Si) - (R1 - S1)|
Rx Maximum Delay = max V(i) / 8
RX Delay Increase Count
– indicates the number of times the delay in jitter buffer is increased during the call.
RX Delay Decrease Count
- indicates the number of times the delay in jitter buffer is decreased during the call.
Please Note:
RTP Statistics is logged only when at least one of the call endpoints is located on the Quadro. For example, it will not be logged when:
•
calls incoming from or addressed to the IP lines or remote extension,
•
calls from an external user are routed to another external user through Quadro’s routing rules.
In the first case, RTP statistics will be logged if remote extension or IP line user is calling locally to the Quadro’s extension or auto attendant.
The
Configure Call Quality Event Notification
link leads to the
Configure Call Quality Event Notification
page where call quality control
notification specifics can be configured.
From the
Configure Call Quality Event Notification
page you may configure event notification policy when the call quality is lower than the allowed
level.
