If there is problem connecting it is likely to be connected to the login. Please check with M5 whether the user can access the required devices
These would normally be intrinsically open. If there is a firewall issue, it is more likely to be a restriction to 'known IP addresses only'
The M5 platform is a hosted solution using Cisco handsets. These handsets typically provide a full range of functionality (ie Answer, Hold, etc.)
Firmware Requirements (for new installations):
The username will be used to download the devices. It needs to be configured to have security access to this information and the ability to monitor these devices.