Four-Channel GSM VoIP Gateway
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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
）
）
）
）
DTMF TYPE
DTMF signals can be sent over to the called party after a call is established. GoIP4
Gateway supports both
Inband
and
Outband
DTMF signal types.
For
Inband
DTMF type, DTMF signals are generated locally at the calling phone and then
send to the called party as part of the voice signals. This method is not reliable since the
quality of the DTMF signals is subject to the Codec used and the quality of the networkt.
For
Outband
DTMF type, DTMF signals are independently translated and sent to the
called party. After receiving DTMF signals, the called party translates and interpret
based on the DTMF protocol. This method allows more reliable DTMF signaling.
However, it requires the called party to support this feature in order for this to work
properly. GoIP4 Gateway supports both RFC2833 and SIP INFO DTMF protocols.
