Audio Configuration - Linksys 900 Series Administrator's Manual

Chapter 5 900 Series phone Field Reference

Audio Configuration

A codec resource is considered as allocated if it has been included in the SDP codec list of an active call,
even though it eventually may not be the one chosen for the connection. So, if the G.729a codec is
enabled and included in the codec list, that resource is tied up until the end of the call whether or not the
call actually uses G.729a. If the G.729a resource is already allocated and since only one G.729a resource
is allowed per device, no other low-bit-rate codec may be allocated for subsequent calls; the only choices
are G711a and G711u. On the other hand, two G.723.1/G.726 resources are available per device.
Therefore it is important to disable the use of G.729a in order to guarantee the support of two
simultaneous G.723/G.726 codec.
Field
Preferred Codec
Silence Supp Enable
Use Pref Codec Only
Silence Threshold
G729a Enable
Echo Canc Enable
G723 Enable
Echo Canc Adapt Enable
G726-16 Enable
Echo Supp Enable
Document Version 3.1
Description
Preferred codec for all calls. (The actual codec used in a call still depends on the outcome
of the codec negotiation protocol.) Select one of the following: G711u, G711a, G726-16,
G726-24, G726-32, G726-40, G729a, or G723.
The default is G711u.
To enable silence suppression so that silent audio frames are not transmitted, select yes.
Otherwise, select no.
The default is no.
To use only the preferred codec for all calls, select yes. (The call fails if the far end does
not support this codec.) Otherwise, select no.
The default is no.
Select the appropriate setting for the threshold: high, medium, or low.
The default is medium.
To enable the use of the G.729a codec at 8 kbps, select yes. Otherwise, select no.
The default is yes.
To enable the use of the echo canceller, select yes. Otherwise, select no.
The default is yes.
To enable the use of the G.723a codec at 6.3 kbps, select yes. Otherwise, select no.
The default is yes.
To enable the echo canceller to adapt, select yes. Otherwise, select no.
The default is yes.
To enable the use of the G.726 codec at 16 kbps, select yes. Otherwise, select no.
The default is yes.
To enable the use of the echo suppressor, select yes. Otherwise, select no.
The default is yes.
Linksys 900 Series IP Phone Administrator Guide
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