User guide

Chapter 4—Configuring your VOIP
Multi-Tech Systems, Inc. 28
Field Name
Values
Description
Default
--
When this button is clicked, all Voice/FAX parameters are set to their default values.
Select Channel
1-2 (210)
1-4 (410)
1-8 (810)
Channel to be configured is selected here.
Copy Channel
--
Copies the Voice/FAX attributes of one channel to another channel. Attributes can be
copied to multiple channels or all channels at once.
Voice Gain
--
Signal amplification (or attenuation) in dB.
Input Gain
+31dB to
–31dB
Modifies audio level entering voice channel before it is sent over the network to the
remote VOIP. The default & recommended value is 0 dB.
Output Gain
+31dB to
–31dB
Modifies audio level being output to the device attached to the voice channel. The
default and recommended value is 0 dB.
DTMF Gain
--
The DTMF Gain (Dual Tone Multi-Frequency) controls the volume level of the DTMF
tones sent out for Touch-Tone dialing.
DTMF Gain,
High Tones
+3dB to
-31dB & “mute”
Default value: -4 dB. Not to be changed except under supervision of Multi-Tech
Technical Support.
DTMF Gain, Low
Tones
+3dB to
-31dB & “mute”
Default value: -7 dB. Not to be changed except under supervision of Multi-Tech
Technical Support.
DTMF Parameters
Duration (DTMF)
60 – 3000 ms
When DTMF: Out of Band is selected, this setting determines how long each DTMF
digit ‘sounds’ or is held. Default = 100 ms.
DTMF
In/Out of Band
Out of Band, or
Inband
When DTMF Out of Band is selected, the MultiVOIP detects DTMF tones at its input
and regenerates them at its output. When DTMF Inband is selected, the DTMF digits
are passed through the MultiVOIP unit as they are received.
Out of Band Mode
RFC 2833,
SIP Info
RFC2833 method. Uses an RTP mode defined in RFC 2833 to transmit the DTMF digits.
SIP Info method. Generates dual tone multi frequency (DTMF) tones on the telephony
call leg. The SIP INFO message is sent along the signaling path of the call.
You must set this parameter per the capabilities of the remote endpoint with which
the VOIP will communicate. The RFC2833 method is the more common of the two
methods.
FAX Parameters
Fax Enable
Y/N
Enables or disables fax capability for a particular channel.
Max Baud Rate
(Fax)
2400, 4800, 7200,
9600, 12000,
14400 bps
Set to match baud rate of fax machine connected to channel (see Fax machine’s user
manual).
Default = 14400 bps.
Fax Volume
-18.5 dB
to –3.5 dB
Controls output level of fax tones. To be changed only under the direction of Multi-
Tech’s Technical Support. Default = -9.5 dB
Jitter Value (Fax)
Default =
400 ms
Defines the inter-arrival packet deviation (in milliseconds) for the fax transmission. A
higher value will increase the delay, allowing a higher percentage of packets to be
reassembled. A lower value will decrease the delay allowing fewer packets to be
reassembled.
Mode (Fax)
FRF 11; T.38
FRF11 is frame-relay FAX standard using these coders: G.711, G.728, G.729, G.723.1.
T.38 is an ITU-T standard for real time faxing of Group 3 faxes over IP networks. It
uses T.30 fax standards and includes special provisions to preclude FAX timeouts
during IP transmissions.
Coder Parameters
Coder
Manual or
Automatic
Determines whether selection of coder is manual or automatic. When Automatic is
selected, the local and remote voice channels will negotiate the voice coder to be used
by selecting the highest bandwidth coder supported by both sides without exceeding
the Max Bandwidth setting. G.723, G.729, or G.711 is negotiated.
Selected Coder
G.711 a/u law 64
kbps;
G.726, @
16/24/32/40
kbps;
G.727, @ nine
Select from a range of coders with specific bandwidths. The higher the bps rate, the
more bandwidth is used. The channel that you are calling must have the same voice
coder selected.
Default = G.723.1 @ 6.3 kbps, as required for H.323. Here 64K of digital voice is
compressed to 6.3K, allowing several simultaneous conversations over the same
bandwidth that would otherwise carry only one.