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Modules COMtrexx Flex
The following modules are available for extending the COMtrexx Flex:
•COMtrexx Flex GbE NET Module: By upgrading with a COMtrexx Flex GbE NET module, there are now two networks with different IP address ranges available.
*Further help under Network interface (second)
•4FXS Module: By upgrading with a COMpact 4FXS module, there are now four internal ports for analogue devices (telephones, fax machines, door stations, announcement outputs) available.
*Further help under Fax
*Further help under Door functions
*Further help under Loudspeaker Audio Out
*Important: Installed and configured 4FXS modules reduce the available VoIP operation modes and therefore also the maximum number of available VoIP channels.
*Further help under VoIP telephony
Configuration 
•Configuring installed modules.
−Hardware