Audio; Optimising Voice Quality For Voip Connections - Gigaset N510 IP PRO Manual

Configuring the phone via the Web configurator

Optimising voice quality for VoIP connections

Functions to improve the voice quality on VoIP connections are available on the Web
page:
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Settings Telephony
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 com-
pressed. 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
connection 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 speech 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 for the other codecs (High Definition Sound Performance).
G.711 a law / G.711 μ law
Excellent voice quality (comparable with ISDN). The necessary 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).
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Audio