The 4400 Voice Compression Module provides 16 channels, of 8kbps, G.729a based
compression and can be deployed to provide a higher density of calls between Call Servers over low speed WAN links. A further 16 channels of voice compression can be enabled per Voice Compression Module via a licence – giving a maximum of 32 compression channels per module (please refer to the Licensing section on page 23 for further information). By using a standard LAN for interconnectivity between the Voice Compression Module and its associated Call Server, there is no limit to the number of compression channels that can be practically deployed.
This allows multiple 4400 Voice Compression Modules to be used with single or multiple Call Servers, with the compression channels being dynamically allocated as, or when, required.
1 Connect the VCM to the system via the LAN port on the front of the VCM Module.
This can be either via the network or directly to a LAN port on the Call Server.
2 Power up the VCM.
3 The module will request an IP address from a DHCP server. It will make 4 attempts and then back off for a period before trying again. The back off period will extend for each failed attempt.
4 Having obtained an IP address the module broadcasts to find a Call Server to provide its configuration and become active.
5 The SpliceCom LED will become solid when the unit is ready.
6 Within Manager, from the Management Information list select Unassigned Modules 7 The VCM will be displayed together with its MAC address
8 Select this link
9 The Module Status field will display “Available”
10 From the Module Status list box select “Member”
11 Select Submit when ready
12 This unit will now be listed under Modules
LAN Port
Power socket
For information on installing a Voice Compression card please refer to page 40.
A Voice Compression Module or Card will required at both ends to provide compression for calls between two Call Servers.
Configuring a Voice Compression Module
1 From the Management Information list select Modules
2 The VCM (SpliceCompressor) will be displayed together with its MAC address 3 Select this link to view and configure this module.
4 For example, you may wish to edit the Name and Description of this module to give an identity and location for future reference.
5 Select Submit when ready
6 Click on Home to return to the Management Information list
The Location field indicates to which Call Server the VCM is registered. The Call Server is responsible for replicating relevant configuration information to the VCM. In turn the VCM will store in RAM configuration information relevant to its functionality.
The Flash LED button will instruct the VCM’s SpliceCom LED to flash. This feature is useful when multiple VCMs are being used on a system and will identify the physical VCM from its corresponding configuration form.
The Product Version field will display which version of software is currently running on the VCM. For information on upgrading this software please refer to page 186.
Setting the IP Address
When connecting a VCM to the system for the first time a DHCP server is required to give the VCM an IP address. This address can be viewed within the VCM’s configuration form as described above. However once connected the Voice Compression Module can be given a static address as follows:
1 From the Management Information list select Modules 2 Select the VCM (SpliceCompressor)
3 Under the first tab within the IP Address field enter the IP Address to be used by the Call Server.
4 Select Submit when ready and you will be returned to the Module List.
5 Reboot the VCM (please refer to page 182 for information on how to reboot a VCM.) A list of each module’s IP address can be viewed in Manager by selecting System and then IP Addresses.
Creating an Intramodule Trunk
In order to use the compression provided by a Voice Compression Module or Card (see below) the following should be configured. For calls between two Call Servers a Voice Compression Module or Voice Compression Card is required at both ends together with the following configuration.
1 From the Management Information list select Modules
2 Select the Call Server to which the VCM is connected or in which the card has been installed.
3 Select the Intramodule Trunks tab 4 Click on Add Intramodule Trunk
5 In the Name field enter a name to identify this trunk
6 In the Capacity field enter the number of connections to be allowed on this link 7 From the Compression Type list box select G729A8K
8 Select Submit when ready and you will be returned to the list of Intramodule Trunks 9 Select the new Intramodule Trunk
10 Click within the Member field and the list of Modules on the system will appear 11 Select the Call Server at the other end
12 Submit the entry
13 Repeat steps 10 to 12 until all the required Call Servers that have a VCM connected or containing a Voice Compression Card have been entered.
14 Select Submit at the top to save the changes
If calls are to be made to a Call Server that does not contain a Voice Compression Card or does not have a Voice Compression Module connected it is recommended that the following
Intramodule Trunk is also created.
If fax calls are to be made between two Call Servers where compression is supported the following Dial Plan entry should be created within each fax machine’s Dial Plan.. The
DialTransparent Action will allow calls to by-pass an Intramodule Trunk. A call made via this Dial Plan entry does not consume a compression channel. (For further information on Dial Plans please refer to page 74.)