User's Manual
Table Of Contents
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HT812/HT814 User Guide 
NAT Settings   
If you plan to keep the Handy Tone within a private network behind a firewall, we recommend using STUN 
Server. The following three settings are useful in the STUN Server scenario:   
1.  STUN Server (under advanced settings webpage) Enter a STUN server IP (or FQDN) that you may 
have, or look up a free public STUN Server on the internet and enter it on this field. If using Public IP, 
keep this field blank.   
2.  Use  Random  SIP/RTP  Ports  (under  advanced  settings  webpage)  This  setting  depends  on  your 
network settings. Generally, if you have multiple IP devices under the same network, it should be set 
to Yes. If using a public IP address, set this parameter to No. 
3.  NAT traversal (under the FXS web page) Set this to Yes when gateway is behind firewall on a private 
network.   
DTMF Methods   
The HT812/HT814 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 HT812/HT814 support following voice codecs. On FXS ports pages, choose the order of your favorite 
codecs:   
 PCMU/A (or G711µ/a)   
 G729 A/B   
 G723.1   
 G726 (16/24/32/40)   
 iLBC 
 OPUS 
Figure 9: Web HTTP Port 










