Gigaset C530 IP Manual Del Usuario página 110

Gigaset C530 IP / LUG - USA en / A31008-XXXXX-XXXX-X-XX / web-conf.fm / 25.03.2015
Optimising voice quality for VoIP connections
Functions to improve the voice quality on VoIP connections are available on the web page:
¤
Settings
The voice quality for VoIP connections is mainly determined by the voice codec used for
transferring the data and the available bandwidth of your DSL connection.
In the case of the voice codec, the voice data is digitised (coded/decoded) and compressed. A
"better" codec (better voice quality) means more data needs to be transferred, i.e. perfect voice
data transfer requires a DSL connection with a larger bandwidth.
You can change the voice quality by selecting (bearing in mind the bandwidth of your DSL
connection) the voice codecs your phone is to use, and specifying the order in which the codecs
are to be suggested when a VoIP connection is established.
Default settings for the codecs used are stored in your phone; one setting optimised for low
bandwidths and one for high bandwidths.
You can generally select one of these standard settings for all VoIP connections on your phone.
If your DSL connection has a low bandwidth, you can also exclude parallel VoIP connections to
increase the voice quality.
You can also change the settings for the voice codecs yourself by selecting the voice codecs to
be used for each VoIP connection on your phone and specifying the sequence in which they
should be suggested when establishing a VoIP connection.
The following voice codecs are supported by your phone:
G.722
Excellent voice quality. The broadband voice codec G.722 works at the same bit rate as G.711
(64 kbit/s per speech connection) but with a higher sampling rate. This allows higher
frequencies to be played back. The speech tone is therefore clearer and better than with the
other codecs (High Definition Sound Performance).
G.711 a law / G.711 μ law
Excellent voice quality (comparable with ISDN). The required bandwidth is 64 kbit/s per voice
connection.
G.726
Good voice quality (inferior to that with G.711 but better than with G.729).
Your phone supports G.726 with a transmission rate of 32 kbit/s per voice connection.
G.729
Average voice quality. The necessary bandwidth is less than or equal to 8 kbit/s per voice
connection.
To save additional bandwidth and transmission capacity on VoIP connections that use the
G.729 codec you can suppress the transmission of voice packets in pauses ("silence
suppression"). Instead of the background noises in your environment, your caller then hears
a synthetic noise generated in the receiver (option: Enable Annex B for codec G.729).
¤
Telephony Audio
Configuring the phone via the Web configurator
109