User guide

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MultiVOIP 400/800 User Guide
20. You can enable the voice/fax advanced features by clicking (checking) the silence compression,
echo cancellation, or forward error correction options.
The Silence Compression option defines whether silence compression is enabled (checked) for
this voice channel. If silence compression is enabled, the MultiVOIP 400/800 will not transmit
voice packets when silence is detected, thereby reducing the amount of network bandwidth that
is being used by the voice channel.
The Echo Cancellation option defines whether echo cancellation is enabled (checked) for this
voice channel. If echo cancellation is enabled, the MultiVOIP 400/800 will remove echo which
improves the quality of sound.
The Forward Error Correction (FEC) option defines whether forward error correction is enabled
(checked) for this voice channel. The FEC feature allows 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.
Note: After configuring a given channel, you can copy that channel’s configuration by clicking the
Copy button and everything on the Voice/Fax tab will be copied to the designated channel.
21. The Billing/Misc tab displays the parameters for auto call, automatic disconnection, billing
options, and dynamic jitter buffer.
If you want to dedicate a local voice/fax channel to a remote voice/fax channel (so you will not
have to dial the remote channel), click the Auto Call Enable option in the Auto Call group. Then
enter the phone number of the remote MultiVOIP 400/800 in the Phone Number field.
22. The Automatic Disconnection group provides three options to be used singly or in combination.
The Jitter Value defines the average inter-arrival packet deviation (in milliseconds) before the
call is automatically disconnected. Jitter is the inter-arrival packet deviation (phase shift of digital
pulses) over the transmission medium that causes voice breakup which can be particularly
disruptive to voice communications. The default setting is 20 milliseconds. A higher value means
that the voice transmission will be more accepting of jitter. A lower value will be less tolerant of
jitter.
Consecutive Packets Lost defines the number of consecutive packets that are lost after which
the call is automatically disconnected. The default setting is 30.