ATCOM APBX IP2G4A User Manual page 38

APBX IP2G4A User Manual
RTP Port Min / Max
Set the RTP port range.
DTMF Mode
Set the default DTMF mode
2) NAT
Here provide other two solutions for SIP one-way-audio issue besides outbound proxy. Using any one is OK.
a. STUN
Just setting STUN server / port is OK.
There are many public STUN server on Internet: http://www.voip-info.org/wiki/view/STUN
b. NAT
The External IP, External Host and Local Network Identification settings are used if you use APBX behind a NAT
device to communicate with services on the outside.
External IP address
Address that we're going to put in outbound SIP messages if we're behind a NAT. The externip and localnet is used
when registering and communicating with other proxies that we're registered with.
External Host
Alternatively you can specify an external host, and APBX will perform DNS queries periodically. Not recommended
for production environments! Use External IP instead.
External Refresh Interval
37 ATCOM TECHNOLOGY CO., LIMITED