Grandstream Networks GRP261X Administration Manual page 53

Use First Matching
Vocoder in 200OK SDP
Codec Negotiation
Priority
Hide Vocoder
Disable Multiple m line
in SDP
SRTP Mode
SRTP Key Length
Crypto Life Time
Symmetric RTP
Silence Suppression
Jitter Buffer Type
Jitter Buffer Length
Voice Frames Per TX
When it is set to "Yes", the device will use the first matching vocoder in the
received 200OK SDP as the codec. The default setting is "No".
Configures the phone to use which codec sequence to negotiate as the
callee. When set to "Caller", the phone negotiates by SDP codec sequence
from received SIP Invite. When set to "Callee", the phone negotiates by audio
codec sequence on the phone. The default setting is "Callee".
When option Hide Vocoder is set as Yes, the coded will be hidden from call
screen as bellow. The default setting is "No".
When it is set to "No", the device will reply with multiple m lines; Otherwise,
it will reply 1 m line. The default setting is "No".
Enable SRTP mode based on your selection from the drop-down menu.

No

Enabled But Not forced

Enabled and Forced

Optional
The default setting is "No".
Allows users to specify the length of the SRTP calls. Available options are:

AES 128&256 bit

AES 128 bit

AES 256 bit
Default setting is: AES 128&256 bit
Enable or disable the crypto life time when using SRTP. If users set to disable
this option, phone does not add the crypto life time to SRTP header. The
default setting is "Yes".
Defines whether symmetric RTP is supported or not. Default setting is "No".
Controls the silence suppression/VAD feature of the audio codecs except
forG.723 (pending) and G.729. If set to "Yes", a small quantity of RTP
packets containing comfort noise will be sent during the periods of silence. If
set to "No", this feature is disabled. Default setting is "No"
Selects either Fixed or Adaptive for jitter buffer type, based on network
conditions. The default setting is "Adaptive".
Selects jitter buffer length from 100ms to 800ms, based on network
conditions. The default setting is "300ms".
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.
GRP261x/GRP2624/GRP2634 Administration Guide
Version 1.0.5.48
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