User guide

Chapter 4: Configuring Your MultiVOIP GSM
Multi-Tech Systems, Inc. MVPGSM 39
Voice/Fax Parameter Definitions (continued)
Field Name Values Description
AutoCa
l
l
Parameters
Auto Call None,
AutoCall
The AutoCall option enables the local MVPGSM to call a remote SIP endpoint
without the user having to dial a Phone Directory Database number. As soon as
you access the channel, the MVPGSM immediately connects to the SIP end point
identified in the Phone Number box of this option. This function requires an entry
in the Outbound Phone Book of the local MVPGSM.
Generate Local Dial
Tone
Y/N If selected, dial tone will be generated locally while the call is connecting between
gateways. This would be useful if there is a long network delay.
Phone Number -- Phone number used for Auto Call function. This phone number must correspond
to an entry in the Outbound Phone Book of the local MVPGSM.
Dynamic Jitter
Dynamic Jitter
Buffer
Dynamic Jitter defines a minimum and a maximum jitter value for voice
communications. When receiving voice packets from an SIP end point, varying
delays between packets may occur due to network traffic problems. This is called
Jitter. To compensate, the MVPGSM uses a Dynamic Jitter Buffer. The Jitter Buffer
enables the MVPGSM 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 GSM gateways.
Minimum Jitter
Value
60 -
400ms
The minimum dynamic jitter buffer of 60 milliseconds is the minimum delay that
would be acceptable over a low jitter network. Default = 60 ms
Maximum Jitter
Value
60 -
400ms
The maximum dynamic jitter buffer of 400 milliseconds is the maximum delay
tolerable over a high jitter network. Default = 300 ms
Optimization
Factor
0 - 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.
Auto Disconnect
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 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.
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 - 65535 Specifies how long to wait before disconnecting the call when IP network
connectivity with the remote site has been lost. Default = 30 sec
Configurable Payload Type
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.