User manual
FIRMWARE VERSION 1.0.1.38 GXV3175V2 USER MANUAL Page 57 of 138
Preferred Vocoder
This products supports up to 8 different Vocoders: including
G.711(a/μ)(PCMU/PCMA),GSM,G726-32,G.723.1,G.729A/B, G.722 and
L16-256.
When this has been configured, the system will select the preferred vocoder
from the list and the same order is sent with the SDP messages.
The user can change the preferred vocoder priority order by toggling with
the up and down buttons. It is recommended to use the default setting
“PCMU”; if other vocoders are chosen, there could be an audio transmission
error.
Preferred Video Codec
Selects the preferred video codec from the available list. It is recommended
to use H.264.
Enable RFC5168 support
Select Yes to enable RFC5168 support. Default is No.
Video Bit Rate
Rate of information content in a video stream. (Ranges from 32 – 1024
kbps)
H.264 Image Size
Select the type of H.264 compression (4CIF, VGA, WQVGA, CIF, QVGA,
QCIF, QQVGA)
H.264Payload type
Selects the dynamic H.264 codec payload type (ranges from 96-127). The
default setting is 99.
H.263+ Payload type
Selects the H.263+ codec payload type (ranges from 96-127). The default
setting is 103.
L16-256 Payload type
Selects the L16-256 codec payload type (ranges from 96-127). The default
setting is 103.
H.263 Encoder Resolution
Selects the resolution (CIF/QCIF) used for H.263 codec. The default
resolution is CIF.
SRTP Mode
This is option to secure the RTP audio
Silence Suppression
This controls the G723/G729 silence suppression/VAD. If set to Yes, when
no audio is detected, the phone will send a small number of VAD packets
(instead of audio packets). If Set to No, this feature is disabled. The default
setting is No.
Voice Frame per TX
This configures the number of voice frames transmitted per packet. (It is
recommended to set this based on the Ethernet IS packet limitation – 1500
Byte or 120kb/s).
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 example: if the codec is configured to be G.723 and “Voice Frames per