Multi-Tech Systems MULTIVOIP MVP210/410/810 User Manual

Chapter 4: Configuring your VOIP 

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Inc. 

     

 

 

37 

 

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 are negotiated. 

Selected Coder 
(SS models only) 

G.711 a/u law 64 kbps;  
G.726, @ 16/24/32/40 kbps; 
G.727, @ nine bps rates; 
G.723.1 @ 5.3 kbps, 6.3 kbps;
G.729, 8kbps; 
Net Coder @ 
6.4, 7.2, 8, 8.8, 9.6 kbps 

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. 
To make selections from the Selected Coder drop-down list, the 
Manual option must be enabled. 

Selected Coder 

G.711, G.729 
 -or-  
G.729, G.711 

Coder Priority has two options (G.711,G.729 or G.729, G711) on 
the Selected Coder listing of the Coder group on the Voice/Fax 
screen. If G.711 is the higher priority, i.e., G.711 is preferred to 
G729 on the sending side, then G.711, G.729 option is selected. 
Similarly, if G.729 has the higher priority, then G.729, G.711 
option is selected. 
It is used whenever a user wants to advertise both G.711 and 
G.729 coders with higher preference to a particular coder. 

It is useful when the calls are made from a particular channel on 
the VOIP to two different destinations where one supports G.711 
and the other supports G.729. 

Max bandwidth 
(coder) 

11 – 128 kbps 
 

This drop-down list enables you to select the maximum 
bandwidth allowed for this channel.  The Max Bandwidth drop-
down list is enabled only if the Coder is set to Automatic.  
If coder is to be selected automatically (“Auto” setting), then enter 
a value for maximum bandwidth.  

Advanced Features 

 

Silence 
Compression 

Y/N 

Determines whether silence compression is enabled (checked) 
for this voice channel.   
With Silence Compression enabled, the MultiVOIP will not 
transmit voice packets when silence is detected, thereby 
reducing the amount of network bandwidth that is being used by 
the voice channel (default = on). 

Echo 
Cancellation 

Y/N 

Determines whether echo cancellation is enabled (checked) for 
this voice channel.  
Echo Cancellation removes echo and improves sound quality 
(default = on). 

Forward Error 
Correction 

Y/N 

Determines whether forward error correction is enabled 
(checked) for this voice channel.  
Forward Error Correction enables some of the voice packets 
that were corrupted or lost to be recovered. FEC adds an 
additional 50% overhead to the total network bandwidth 
consumed by the voice channel (default = Off).