One-Channel GSM VoIP Gateway
21
The NAT Keep-alive feature sends a null packet to the SIP Proxy periodically in order to
keep the NAT open on your firewall for incoming data traffic.
3.4.3 Advanced Timing
A)
No Answer Expiry(32-180s)
,
NICT Expiry(2-180s)
,
Retransmit T1(200-2000ms)
,
Retransmit T2(2000-8000ms)
Some SIP proxies may have special timing requirements. Change these parameters as
required.
B
）
）
）
）
DTMF Signaling
1
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）
）
）
DTMF TYPE
DTMF signals can be sent over to the called party after a call is established. GoIP1
Gateway supports both
Inband
and
Outband
DTMF signal types.
For
Inband
DTMF type, DTMF signals are generated locally at the calling phone and then
