User's Manual
Grandstream Networks, Inc. GXV3140 USER MANUAL  Page 35 of 83 
 FIRMWARE VERSION 1.0.1.18 Updated : 09/2009 
Messages  validated. 
SIP T1 Timeout  This configures the timeout period for SIP T1. The default setting is 0.5 Seconds
SIP T2 Interval  This configures the time interval for SIP T2. The default setting is 4 seconds. 
Remove OBP from 
route 
The SIP Extension notifies the SIP server that it is behind a NAT/firewall. 
Account/Codec Settings 
Enable Video 
--YES:Accepts all incoming video, this is the default setting; 
--NO:video is disabled. 
DTMF  Assigns the mechanism to send DTMF. There are three supported modes: in 
audio (with DTMF as audio signals), through RTP and through SIP INFO. 
DTMF Payload Type  Sends DTMF using RFC2833. The default is 101. 
Preferred Vocoder  This products supports up to 5 different Vocoders: including G.711(a/μ)
(PCMU/PCMA),GSM,G726-32k,G.723.1,G.729A/B and iLBC 
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 Coder  Selects the preferred video codec from the available list. It is recommended to 
use H.264 
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 
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 TX” is 
set to 2. Then in the INVITE request, the “ptime” value for SDP will be 60 ms. 










