Multi-Tech Systems Multivoip Model Mvp400/800 Standalone Voice/ip Gateway Quick Start Guide

							21 Configuring  the MultiVOIP
16. The Voice/Fax tab displays the parameters for the voice
gain, DTMF (Dual Tone Multi-Frequency) gain, voice
coder, faxing, and advanced features such as Silence
Compression, Echo Cancellation, and Forward Error
Correction.
17. You can set the input and output voice gain so that the
volume can be increased or decreased. Input gain
modifies the level of the audio coming in to the voice
channel before it is sent over the Internet to the remote
MultiVOIP 400/800.  Output gain modifies the level of the
audio being output to the device attached to the voice
channel. Make your selections from the Input and Output
lists in the Voice Gain group. The valid range  is +31dB to
–31dB with a recommended default value of 0.
You can set up the DTMF gain (output level in decibels) for
the higher and lower frequency groups of the DTMF tone
pair.  Make your selections from the High and Low lists in
the DTMF Gain group.  When the DTMF Out of Band
check box is selected, the unit reproduces the DTMF
tones instead of passing them through. 
						

							MultiVOIP Quick Start Guide
22Note: The DTMF gain should be changed only with the
assistance of Multi-Tech Technical Support.
18. To change the voice coder, select the channel from the
Select Channel list, then click Manual in the Coder group.
Select the new voice coder entry from the Selected Coder
list.
If you changed the voice coder, ensure that the same
voice coder is used on the voice/fax channel you are
calling.  Otherwise, you will always get a busy signal.
Note: If you allow the Coder to be selected automatically,
then you need to enter the Max Bandwidth. Check with
your network administrator to determine how much
bandwidth is available.
19. The Fax group enables you to send/receive faxes on the
selected voice/fax channel. You can select the maximum
baud rate for faxes and the fax volume and enter the jitter
value in milliseconds.
When receiving fax packets from a remote MultiVOIP 400/
800, it is possible for individual packets to be delayed or
received out of order due to traffic conditions on the
network. To compensate for this effect, the MultiVOIP 400/
800 uses a Jitter Buffer. The Jitter Value enables the
MultiVOIP 400/800 to wait a user-definable period of time,
in milliseconds, for delayed or out of order fax packets.
The range of allowable Jitter Values is 0 to 400
milliseconds, with a default of 400 milliseconds.
If you do not plan to send or receive faxes on a given
voice/fax channel, you can disable faxes in the Fax group.
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 check box defines whether
silence compression is enabled for this voice channel. If
silence compression is enabled, the MultiVOIP 400/800 
						

							23 Configuring  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.
The Echo Cancellation check box defines whether echo
cancellation is enabled 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) check box 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 Copy.  Everything on
the Voice/Fax tab will be copied to the other channel.
21. The Billing/Misc tab displays the parameters for auto call,
automatic disconnection, billing options, and dynamic jitter
buffer. 
						

							MultiVOIP Quick Start Guide
24If 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), select the Auto Call Enable check box
in the Auto Call group. Then enter the phone number of
the remote MultiVOIP 400/800 in the Phone Number box.
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.
Call Duration defines the maximum length of time (in
seconds) that a call remains connected before the call is
automatically disconnected. The default setting is 180
seconds.  A call limit of three minutes may be too short for
most configurations. Therefore, you may want to increase
this default value.
23. You can set billing options for inbound and/or outbound
calls by checking them in the Billing Options group and
then entering the charge in cents per number of seconds.
24. A minimum and maximum set of values can be set for
Dynamic Jitter Buffer. When receiving voice packets
from a remote MultiVOIP 400/800, it is possible to
experience varying delays between packets due to traffic
conditions on the network. This is called Jitter. To
compensate for this effect, the MultiVOIP 400/800 uses a 
						

							25 Configuring  the MultiVOIP
Dynamic Jitter Buffer. The Jitter Buffer allows the
MultiVOIP 400/800 to wait for delayed voice packets by
automatically adjusting the length of the Jitter Buffer
between allowable 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
effects the voice delay between MultiVOIP 400/800
gateways.
The Minimum Jitter Value default setting is 150
milliseconds, the Maximum Jitter Value default setting is
300 milliseconds, and the Optimization Factor default
setting is 7.
Note: After configuring a given channel, you can copy that
channel configuration to the other channel by clicking
Copy Options. Everything on the Billing/Misc tab will be
copied to the other channel.
If your country/region is not the default USA, click the
Regional tab and proceed to step 25.  Otherwise, proceed
to step 26 to begin building your phone directory database. 
						

							MultiVOIP Quick Start Guide
2625. To change the Tone Pairs on the Regional tab, select your
country or region from the Country/Region list.
Note: If your country or region is not listed, click Custom
to define it.
The Tone Pairs group enables you to select and modify
the parameters.  Click OK when finished. Proceed to step
26 to begin building your phone directory database. 
						

							27 Configuring  the MultiVOIP
26. The Phone Directory Database dialog box displays with
the Proprietary PhoneBook option selected and no
phone numbers entries displayed in the database.  This
dialog box enables you to select either the GateKeeper or
Proprietary PhoneBook.  Once you have selected the type
of Phone Book database, you can proceed to Registering
with a GateKeeper Phone Directory in the following
section.  Or, if you are building a proprietary phone book,
proceed to the Building a Proprietary Phonebook Directory
section later in this manual. 
						

							MultiVOIP Quick Start Guide
28
Registering with a Gatekeeper Phone Directory
This section describes how to register H.323 endpoints
with the Gatekeeper.  The H.323 Gatekeeper function
resides at a PC acting as the central point for all calls
within its zone and providing call control services to
registered endpoints.  The Gatekeeper performs two
important call control functions: address translation from
LAN aliases to IP addresses, and bandwidth management
where the network manager has specified a threshold for
the number of simultaneous conferences on the LAN.
In a GateKeeper environment, you will be selecting the
GateKeeper option, entering an IP address for the
GateKeeper, and accepting the default port number.  If the
GateKeeper network is servicing Fast Start, accept the
defaults in the Q.931 Parameters group.  If this network
zone is primarily non-Fast Start supported, you will clear
the Use Fast Start check box.
1. Select the GateKeeper option.
2. The Use Fast Start check box is selected by default.  If
the GateKeeper network employs Fast Start, leave this
selected.  You may have to verify whether Fast Start is
used with the GateKeeper administrator. 
						

							29 Configuring  the MultiVOIP
3. Enter the Gatekeeper IP Address in the IP Address box of
the RAS Parameters group.
4. Accept the default Port Number 1719.
CAUTION: The default setting for the Gatekeeper Port
Number is 1719. This can be changed to a different value
by the Gatekeeper administrator.  If you decide to change
the default Port Number, you must use the same number
on the Gatekeeper and all other H.323 endpoints.
5. Click Add when you are finished to begin building your
phone directory database. The Add/Edit Phone Entry
dialog box displays.
6. Enter the unique phone number of the local device in the
Phone Number box.  For example, 101.
7. Leave the Description box blank.
8. Enter the Voice Channel number that corresponds to the
phone number entered.
9. Enter a description in the H.323 ID box with a description
to identify the phone number.  For this example, you could
enter “New York Office 1”. 
						

							MultiVOIP Quick Start Guide
3010. Enter the Port IP Address of the MultiVOIP you are
currently configuring in the IP Address box.
11. Click OK when you are finished.  The Phone Directory
Database dialog box displays your first entry.
12. Click Add to enter your next phone listing.  The Add/Edit
Phone Entry dialog box displays.
13. Enter the second unique phone number of the local device
in the Phone Number box.  For example, 102.
14. Leave the Description box blank.