Grandstream Networks DP752 Administration Manual page 54

Disable DTMF Uses above DTMF order without negotiation. Default is No.
Negotiation
DTMF Payload Type Defines payload type for DTMF using RFC2833.
Vocoder Settings
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.
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. Default is No.
SDP
Callee Codec When callee, whose codecs are given priority in Codecs negotiation, local or
Negotiation Priority remote. Set it Remote will use remote codec priority, or local will use local priority.
Default is Remote.
SRTP Mode Selects SRTP mode to use ("Disabled", "Enabled but not forced", or "Enabled and
forced"). Default is Disabled.
It uses SDP security description to exchange key. Please refer to:
SDES:
SRTP:
Crypto Life Time Adds crypto life time header to SRTP packets. Default is Yes.
https://tools.ietf.org/html/rfc4568
https://tools.ietf.org/html/rfc3711
DP752/DP730/DP722 Administration Guide
Version 1.0.11.4
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