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

Chapter 4: Configuring your VOIP 

Multi-Tech 

Systems, 

Inc. 

     

 

 

39 

 

Field Name 

Values 

Description 

Dynamic Jitter Buffer 

 

Dynamic Jitter defines a minimum and a maximum jitter value for voice 
communications. When receiving voice packets from a remote MultiVOIP, 
varying delays between packets may occur due to network traffic problems. 
This is called Jitter. To compensate, the MultiVOIP  uses a Dynamic Jitter 
Buffer.  The Jitter Buffer enables the MultiVOIP to wait for delayed voice 
packets by automatically adjusting the length of the Jitter Buffer between 
configurable minimum and maximum values. An Optimization Factor 
adjustment controls how quickly the length of the Jitter Buffer is increased 
when jitter increases on the network. The length of the jitter buffer directly 
affects the voice delay between MultiVOIP gateways. 

Minimum Jitter Value 

60 to 400 
ms 

The minimum dynamic jitter buffer of 60 milliseconds is the minimum delay 
that would be acceptable over a low jitter network. 
Default = 150 ms 

Maximum Jitter Value  60 to 400 

ms 

The maximum dynamic jitter buffer of 400 milliseconds is the maximum delay 
tolerable over a high jitter network. 
Default = 300 ms 

Optimization Factor 

0 to 12 

The Optimization Factor determines how quickly the length of the Dynamic 
Jitter Buffer is changed based on actual jitter encountered on the network. 
Selecting the minimum value of 0 means low voice delay is desired, but 
increases the possibility of jitter-induced voice quality problems. Selecting the 
maximum value of 12 means highest voice quality under jitter conditions is 
desired at the cost of increased voice delay.  
Default = 7. 

Automatic 
Disconnection  

-- 

The Automatic Disconnection group provides four options which can be 
used singly or in any combination.  

Jitter Value 

1-65535 

The Jitter Value defines the average inter-arrival packet deviation (in 
milliseconds) before the call is automatically disconnected. The default is 300 
milliseconds. A higher value means voice transmission will be more accepting 
of jitter. A lower value is less tolerant of jitter. 
Inactive by default. When active, default = 300 ms.  However, value must 
equal or exceed Dynamic Minimum Jitter Value.  

Call Duration 

1-65535 

Call Duration defines the maximum length of time (in seconds) that a call 
remains connected before the call is automatically disconnected.  
Inactive by default.   
When active, default = 180 sec. 
This may be too short for some configurations, requiring upward adjustment. 

Consecutive Packets 
Lost 

1-65535 

Consecutive Packets Lost defines the number of consecutive packets that 
are lost after which the call is automatically disconnected.  
Inactive by default.  
When active, default = 30 

Network 
Disconnection 

1 to 65535;  
Default = 
30 sec. 

Specifies how long to wait before disconnecting the call when IP network 
connectivity with the remote site has been lost. 

 

(Not available on the –SS series) 

The Configurable Payload Type is located on the bottom of the Voice/Fax screen.  The Configurable Payload 
Type is used when the remote side uses a different payload type for the associated features. In previous 
firmware versions, MultiVOIP’s used 101 for DTMF RFC2833. If the remote side uses some other dynamic 
payload type such as 110, it will fail. To avoid these failures, the payload types are made configurable. 

DTMF RFC2833 Configurable Payload Type is supported only for SIP & SPP and not for H.323.  
Whenever you interoperate with older MultiVOIP products (i.e., earlier than release x.11), for backward 
compatibility, make sure to configure the payload type values to default ones, which match the values of 
older MultiVOIP’s.