User's Guide
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HT81x User Guide 
DTMF Methods 
The HT81X support the following DTMF mode: 
 DTMF in-audio   
 DTMF via RTP (RFC2833)   
 DTMF via SIP INFO   
Set priority of DTMF methods according to your preference. This setting should be based on your server 
DTMF setting.   
Preferred Vocoder (Codec) 
The HT81X support following voice codecs. OnProfile pages, choose the order of your favorite codecs:   
 PCMU/A (or G711µ/a)   
 G729 A/B   
 G723.1   
 G726 
 iLBC 
 OPUS 










