Why I cannot make two VoIP calls at the same time? When try to make a 2nd call the display always shows "not possible".

If you wish to permit two VoIP connections, do the following steps: 

• Open the Web Configurator
• Open the menu "Settings" - "Telephony" - "Audio"
• Activate the option "No" next to "Allow 1 VoIP call only"

Please Note: If, however, your DSL connection has a narrow bandwidth, there may be problems if two VoIP calls are made at the same time.The data is no longer transferred properly(long voice delay, datalosses etc.).