Specifications

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Linksys IP Phone Administrator Guide
Document Version 3.2
Chapter 5 Linksys ATA Field Reference
PSTN Line Tab
Audio Configuration (SPA3102/AG310)
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 G729a 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 Description
Preferred Codec 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.
Silence Supp Enable To enable silence suppression so that silent audio frames are not transmitted, select yes.
Otherwise, select no.
The default is no.
Use Pref Codec Only 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.
Silence Threshold Select the appropriate setting for the threshold: high, medium, or low.
The default is medium.
G729a Enable To enable the use of the G729a codec at 8 kbps, select yes. Otherwise, select no.
The default is yes.
Echo Canc Enable To enable the use of the echo canceller, select yes. Otherwise, select no.
The default is yes.
G723 Enable To enable the use of the G723a codec at 6.3 kbps, select yes. Otherwise, select no.
The default is yes.
Echo Canc Adapt Enable To enable the echo canceller to adapt, select yes. Otherwise, select no.
The default is yes.
G726-16 Enable To enable the use of the G726 codec at 16 kbps, select yes. Otherwise, select no.
The default is yes.
Echo Supp Enable To enable the use of the echo suppressor, select yes. Otherwise, select no.
The default is yes.
G726-24 Enable To enable the use of the G726 codec at 24 kbps, select yes. Otherwise, select no.
The default is yes.