User's Manual
Table Of Contents
FIRMWARE 1.0.3.4  GXW42XX USER MANUAL  PAGE 42 OF 56 
Preferred DTMF 
method (in listed 
order) 
The  GXW4248  supports up to 3  different  DTMF methods including  in-audio, via RTP 
(RFC2833) and via Sip Info. The user can configure DTMF method in a priority list. 
Disable DTMF 
Negotiation 
Default is No. If set to yes, use above DTMF order without negotiation 
DTMF Payload 
Type 
Sets the payload type for DTMF using RFC2833. 
Preferred Vocoder 
The  GXW4248  supports up to 5 different Vocoder types including G.711 A-/U-law, G.726 
(Supports bit rates 16, 24, 32 and 40), G.723.1, G.729A/B, iLBC
. The user can configure 
Vocoders in a preference list that will be included with the same preference order in SDP 
message. The first Vocoder is entered by choosing the appropriate option in 
“Choice 1”. The 
last Vocoder is entered by choosing the appropriate option in “Choice 8”. 
Voice Frames per 
TX 
Number of the frame size when it transmits. Default is 2, from 1 -4 for G711/G726/G729 
G723 Rate 
Defines the encoding rate for G.723 vocoder. By default, 6.3kbps rate is chosen. 
G726-32 Packing 
Mode 
Choose the packing mode for G726-32 
iLBC Frame Size 
Sets the iLBC frame size in 20ms or 30ms 
iLBC Payload type 
Default value is 97. Defines payload type for iLBC. The valid range is between 96 and 127. 
AAL2-G726-16 
Payload type 
Default value is 100. Range is from 96 to 127.  
AAL2-G726-24 
Payload type 
Default value is 99. Range is from 96 to 127. 
AAL2-G726-32 
Payload type 
Default value is 104. Range is from 96 to 127. 
AAL2-G726-40 
Payload type 
Default value is 103. Range is from 96 to 127. 
Use First 
Matching Vocoder 
in 200OK SDP 
Default is No. If set to “Yes”,  device will include only the first match vocoder in its 200OK 
response, otherwise it will include all match vocoders in same order received in INVITE. 










