Grandstream Networks DP750 Administration Manual page 53

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.
Callee Codec When callee, whose codecs are given priority in Codecs negotiation, local or
remote. Set it Remote will use remote codec priority, or local will use local priority.
Negotiation Priority
Default is Remote.
Selects SRTP mode to use ("Disabled", "Enabled but not forced", or "Enabled and
SRTP Mode
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.
Silence Allows detecting the absence of audio and conserves bandwidth by preventing the
Suppression (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.
 High (initial 200ms, min 40ms, max 600ms) Note: not all vocoders can meet
Jitter Buffer Length
 Medium (initial 100ms, min 20ms, max 200ms).
 Low (initial 50ms, min 10ms, max 100ms).
Enable RTCP Enables RTCP statistics and control information. Default settings is RTCP.
Call Settings
Sends an early INVITE each time a key is pressed when a user dials a number.
Early Dial
Otherwise, only one INVITE is sent after full number is dialed (user presses Dial
Key or after "no key entry timeout" expires). This option should be used only if there
is a SIP proxy configured and supporting "484 Incomplete Address" responses.
Otherwise, the call will likely be rejected by the proxy (with a 404 Not Found error).
Default is No.
This feature is NOT designed to work with and should NOT be enabled for direct
IP-to-IP calling.
Dial Plan Prefix Adds specified prefix to dialed number.
Dial Plan Dial Plan Rules:
1. Accept Digits: +,1,2,3,4,5,6,7,8,9,0, *, #, A,a,B,b,C,c,D,d ;
2. Grammar: x – any digit from 0-9;
https://tools.ietf.org/html/rfc4568
https://tools.ietf.org/html/rfc3711
the high requirement.
DP750/DP720 Administration Guide
Version 1.0.11.4
P a g e | 53