Account/Codec Settings - Grandstream Networks WP820 Administration Manual

Force Timer
Configures the session timer feature on the phone by force. If it is set to "Yes", the
phone will use the session timer even if the remote party does not support this
feature. If it is set to "No", the phone will enable the session timer only when the
remote party supports this feature. To turn off the session timer, select "No".
The default setting is "No".
Force INVITE Sets the SIP message type for refresh the session. If it is set to "Yes", the Session
Timer will be refreshed by using the SIP INVITE message. Otherwise, the phone
will use the SIP UPDATE or SIP OPTIONS message. Default is "No".

Account/Codec Settings

Preferred Vocoder
Preferred Vocoder
Lists the available and enabled Audio codecs for this account. Users can enable
the specific audio codecs by moving them to the selected box and set them with a
priority order from top to bottom. This configuration will be included with the same
preference order in the SIP SDP message. The Supported vocoders are: PCMU,
PCMA, G722, G729A/B, iLBC and Opus.
Codec Negotiation Configures the phone to use which codec sequence to negotiate as the callee.
Priority When set to "Caller", the phone negotiates by SDP codec sequence from
received SIP Invite; When set to "Callee", the phone negotiates by audio codec
sequence on the phone.
Use First Matching Includes only the first matching vocoder in its 200OK response, otherwise it will
Vocoder in 200OK include all matching vocoders in same order received in INVITE.
SDP Default is No.
iLBC Frame Size Specifies iLBC packet frame size (20ms or 30ms). Default is 30ms.
Opus Payload Type Determines payload type for Opus codec. The valid range is between 96 and 126.
Default is 123.
DTMF
Specifies the mechanism to transmit DTMF (Dual Tone Multi-Frequency) signals.
There are 3 supported modes: The default setting is "RFC2833".
• In audio, which means DTMF is combined in the audio signal (not very reliable
with low-bit-rate codecs);
• RFC2833, which means to specify DTMF with RTP packet. Users could know
the packet is DTMF in the RTP header as well as the type of DTMF.
• SIP INFO, which uses SIP INFO to carry DTMF. The defect of this mode is that
it's easily to cause desynchronized of DTMF and media packet if the SIP and RTP
messages are required to transmitted respectively.
WP820 Administration Guide
Version 1.0.1.15
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