User Guide

GRP26XX Administration Guide
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Jitter Buffer Length
Selects jitter buffer length from 100ms to 800ms, based on network
conditions. The default setting is “300ms”.
Voice Frames Per TX
Configures the number of voice frames transmitted per packet. When
configuring this, it should be noted that the “ptime” value for the SDP will
change with different configurations here. This value is related to the codec
used and the actual frames transmitted during the in-payload call. For end
users, it is recommended to use the default setting, as incorrect settings may
influence the audio quality. The default setting is 2.
G723 Rate
This option determines the encoding rate for G723 codec. Users can choose
from 6.3kbps encoding rate and 5.3kbps encoding rate.
The default setting is “5.3kbps encoding rate”.
G.726-32 Packing
Mode
Selects “ITU” or “IETF” for G726-32 packing mode. The default setting is
“ITU”.
iLBC Frame Size
This option determines the iLBC packet frame size. Users can choose from
20ms and 30ms. The default setting is “30ms”.
iLBC Payload Type
This option is used to specify iLBC payload type. Valid range is 96 to 127.
The default setting is “97”.
OPUS Payload Type
Specifies OPUS payload type. Valid range is 96 to 127. Cannot be the same
as iLBC or DTMF Payload Type. Default value is 123.
DTMF Payload Type
Configures the payload type for DTMF using RFC2833. Cannot be the same
as iLBC or OPUS payload type.
Send DTMF
This parameter specifies the mechanism to transmit DTMF digits. There are
3 supported modes:
• In audio: DTMF is combined in the audio signal (not very reliable with low-
bit-rate codecs);
• RFC2833 sends DTMF with RTP packet. Users can check the RTP packet
to see the DTMFs sent as well as the number pressed.
• SIP INFO uses SIP INFO to carry DTMF.
Default setting is “RFC2833”.
DTMF Delay
Configures the delay between sending DTMF during MPK/VPK use (in
milliseconds).
Account x → Call Settings
Early Dial
Selects whether to enable early dial. If it’s set to “Yes”, the SIP proxy must
support 484 responses. Early Dial means that the phone sends for each
pressed digit a SIP INVITE message to SIP server. SIP server considers its
extensions and, if no match happened yet, it sends back a “484 Address
Incomplete” message. Otherwise, it executes the action.
The default setting is “No”.