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.