Grandstream Networks DP750 Administration Manual page 52

Trusted CA Treats entered certificate as a valid CA for authenticating the server TLS certificate.
Certificate Default is No.
Audio Settings
Send DTMF Specifies the mechanism to transmit DTMF digits. There are 3 supported modes:
 In audio: which means DTMF is combined in the audio signal (not very reliable
 Via RTP (RFC2833): permits to specify DTMF with RTP packet. Users could
 SIP INFO: uses SIP INFO to carry DTMF. The defect of this mode is that it's
Default is via RTP (RFC2833)
Disable DTMF Uses above DTMF order without negotiation.
Negotiation Default is No.
DTMF Payload Type Defines payload type for DTMF using RFC2833.
Preferred Vocoder Configures vocoders in a preference list (up to 8 preferred vocoders) that will be
included with same order in SDP message. Vocoder types are G.711 A-/U-law,
G.722, G.726-32, G.723, G.729, iLBC and OPUS
Voice Frames per Transmits a specific number of voice frames per packet. Default is 2; increases to
TX 10/20/32/64 for G711/G726/G723/other codecs respectively.
G723 Rate Operates at specified encoding rate for G.723 vocoder. Available encoding rates
are 6.3kbps or 5.3kbps. Default is 6.3kbps.
G726-32 Packing Defines G726-32 packing mode ("ITU" or "IETF"). Default is ITU.
Mode
iLBC Frame Size Specifies iLBC packet frame size (20ms or 30ms). Default is 20ms.
iLBC Payload type Determines payload type for iLBC. The valid range is between 96 and 127.
Default is 97.
Disable OPUS Disables OPUS stereo attribute in SDP header. Default is No.
stereo in SDP
OPUS Payload Type Determines OPUS payload type. The valid range is between 96 and 127.
Default is 125.
with low-bit-rate codecs);
know the packet is DTMF in the RTP header as well as the type of DTMF;
easily to cause desynchronized of DTMF and media packet for the reason the
SIP and RTP are transmitted respectively.
DP750/DP720 Administration Guide
Version 1.0.11.4
P a g e | 52