Can a company network firewall prevent connection to the alarm dialler?

Yes, that’s possible. In some situations, there may be problems connecting to the Octalarm portal (portal.octalarm.com) due to a firewall in the company network.

This is resolved as follows

In case your network has a firewall that blocks all outgoing and incoming connections by default, you will need to make adjustments to your firewall when using the web interface.

See Firewall company network for further explanation.