User's Manual

Server set-up
The IP Deskphone with SIP Software works with Telchemy server software. The name of the
software is SQmediator and is available through Telchemy (
http://www.telchemy.com). The
minimum version required is release 1.0.
How VQMon works
The IP Deskphone with SIP Software gathers statistics about the current call when VQMon is
enabled. Statistics are also gathered regarding the quality metrics of the current call. The call-
related statistics contain condensed information about the SIP Session Description Protocol
(SDP), the Call ID, the local and remote address, voice quality-related statistics, Zulu times for
start-time and the time the report was sent.
The voice quality-related statistics include jitter, packet loss, delay, burst gap loss, listening R-
factor, R-LQ, R-CQ, MOS-LQ and MOS-CQ. See
Table 15: Glossary of RTCP XR metrics on
page 138. More information on each of these metrics is provided in RFC3611 “RTP Control
Protocol Extended Reports (RTCP XR)”.
When the IP Deskphone detects that a particular voice quality metric has exceeded a threshold
(defined in the device configuration file), the IP Deskphone sends a message to the server
indicating that there is an issue. If the issue persists, then the IP Deskphone reports another
message at regular intervals indicating that there is an exceeded value. This happens
continuously until the voice quality metric falls below the threshold value. As well, the
IP Deskphone can send regular reports of the voice quality at time intervals defined in the
device configuration file.
Table 15: Glossary of RTCP XR metrics
Metric
Description
Burst A period of high packet losses and / or
discards. A burst is calculated in
milliseconds.
Conversational R-factor Voice quality metric based on burst packet
loss and vocoder selection.
Delay One way delay which includes end-to-end
delay, jitter buffer delay and packetization
delay. Delay is calculated in milliseconds.
Inter-arrival jitter The variation in packet arrival times due to
transmission (routing, queuing delay)
through the network. Jitter is calculated in
milliseconds.
Listening R-factor Voice quality metric based on burst packet
loss, transmission delay and burst loss.
Features
138 SIP Software for Avaya 1100 Series IP Deskphones-Administration November 2012
Comments? [e-mail]