ATL Telecom IP250 - Manual (Page 20)

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4 CODECS
If the device is running one of the four VoIP applications, the following page is available for
configuring the audio CODEC parameters, as well as the Jitter Buffer settings for the CODEC
decoders.
Enter which CODECs are to be supported. For some protocols (e.g. H.323 and SIP), the
G711U and G711A protocols are always supported by default. For MGCP and H.248, it is
possible to remove these CODECs from the devices list of supported “capabilities”.
Select which complex codec is to be supported. Due to memory limitations, it is not possible
to select more than one complex codec.
Select the packetization period to be used for each selected CODEC. For MGCP, a range of
packetizations may be provided for each CODEC (to be advertised in the device’s “capabilities”
set).
Select whether Silence Suppression is to be supported for each CODEC.
The Jitter Buffer settings apply to all active CODEC decoders. You may choose between an
adaptive jitter buffer and a fixed jitter buffer. For an adaptive jitter buffer, choose the maximum
allowable playout delay (in milliseconds). For a fixed jitter buffer, choose the fixed playout
delay (in milliseconds).
Finally, select whether or not a decoder should automatically switch from an adaptive
jitter buffer to a fixed jitterbuffer upon fax/modem tone detection. Adaptive jitter buffers
are sometimes detrimental to fax transmission over G711 CODECs if they have to adapt
too rapidly or too extensively due to inconsistent and widespread packet delays. In these
adverse network conditions, a fixed jitter buffer provides superior performance when handling
incoming fax transmissions over G711 CODECs. Press “Save CODEC Settings” to save the
new CODEC parameters.
5 SySTEM
5.1 Security
The password needed to access the VoIP device via web interface can be set in the following
page. First enter the old password, then enter the new password and confirm the new
password. Click on the Change Password button to save the change. The VoIP device will log
the user out and redirect the user to the login page.