Phones on my network are being spam called by an IP address

People on my phone network has been getting spam called by a local IP address and a number call “277277277277277277” in my freepbx system. Is there a way to stop this from happening? here are some screenshots.

Fix your firewall, they are scanning your network for open SIP ports and sending calls to it.

If you don’t listen for SIP on UDP:5060 they will likely go away.

you want me to enable the firewall?

You don’t have the firewall enabled on a publicly facing system?

i enabled firewall and now everyone outside my network has their phones not working