Grandstream Networks DP720 Administration Manual page 39

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 TX Transmits a specific number of voice frames per packet. Default is 2; increases to
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.
Defines G726-32 packing mode ("ITU" or "IETF"). Default is ITU.
G726-32 Packing
Mode
iLBC Frame Size Specifies iLBC packet frame size (20ms or 30ms). Default is 20ms.
Determines payload type for iLBC. The valid range is between 96 and 127.
iLBC Payload type
Default is 97.
Disable OPUS stereo Disables OPUS stereo attribute in SDP header. Default is No.
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 include all
Vocoder in 200OK matching vocoders in same order received in INVITE. Default is No.
SDP
Selects SRTP mode to use ("Disabled", "Enabled but not forced", or "Enabled and forced").
SRTP Mode
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.
Silence Suppression Allows detecting the absence of audio and conserves bandwidth by preventing the
(VAD) transmission of "silent packets" over the network.
Default is No.
Jitter Buffer Type Selects jitter buffer type (Fixed or Adaptive) based on network conditions.
Jitter Buffer Length
https://tools.ietf.org/html/rfc4568
https://tools.ietf.org/html/rfc3711

High (initial 200ms, min 40ms, max 600ms) Note: not all vocoders can meet the
high requirement.

Medium (initial 100ms, min 20ms, max 200ms).

Low (initial 50ms, min 10ms, max 100ms).
DP750/DP720 Administration Guide
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