Siemens Gigaset S675IP User Manual page 105

Web configurator
If the receiving device does not accept
any of the voice codecs in the
codecs list, the connection is not estab-
lished. An appropriate message will be
displayed on the handset.
If the phone always starts by trying to
establish a broadband connection, put
the G.722 codec at the top of the list
Selected codecs.
Please note:
– You should only deactivate codecs (put
them in the Available codecs
particular reason. The more codecs that are
deactivated, the greater the danger that
calls will not be able to be established due
to unsuccessful codec negotiations. In par-
ticular you can only establish broadband
connections if you permit the
– With incoming calls, all supported voice
codecs are always permitted.
Area: Settings for Codecs
To save additional bandwidth and trans-
mission capacity, on VoIP connections that
use the codec you can suppress the
G.729
transmission of voice packets in pauses
("Silence Suppression"). Then, instead of
the background noises in your environ-
ment, your caller hears a synthetic noise
generated in the receiver.
Please note: "Silence Suppression" can
sometimes lead to deterioration in the
voice quality.
¤
In the Enable Annex B for codec G.729
field, state whether the transmission of
data packets during pauses should be
suppressed when using the
codec, (activate Yes).
104
Selected
list) if there is a
codec
G.722
G.729
Saving settings on the phone
¤
Click Set to save the settings for the
voice quality.
Please note:
You should observe the following for good
voice quality:
– When making calls using VoIP, avoid per-
forming other Internet activities (e.g. surf-
ing the Internet).
– Irrespective of the codec used and the net-
work capacity utilisation, please note that
voice delays can occur.
Voice quality and infrastructure
With your Gigaset S675 IP you have the
opportunity to make calls with good voice
quality via VoIP.
However, your phone's performance with
VoIP – and therefore the voice quality –
also depends on the properties of the
entire infrastructure.
The following VoIP provider components
are just some of the things that can influ-
ence performance:
u
Router
u
DSLAM
u
DSL transmission line and speed
u
Connection paths over the Internet
u
If necessary, other applications that
also use the DSL connection
In VoIP networks, voice quality is affected
by various things including the "quality of
service" (QoS). If the entire infrastructure
demonstrates QoS, voice quality is better
(fewer delays, less echoing, less crackling
etc.).
If, for example, the router does not have
QoS, then the voice quality is not as good.
Please see the specialist documentation
for further information.