Before writing any further let me show you an email screenshot one of my client received from VoIP provider.
VoIP provider has charged this company over $6000 in a day, They pay around $16 to $20 every month for their call charges and now they had to pay $6000 in a single day. You can imagine kind of loss to a company.
I don’t want to scare but I want to you to understand how this could impact on your company and how you can secure your PBX to avoid any such situation.
Here are steps you can take.
- Login to PBX web interface then go to settings –> sip settings. Make sure to set no to Allow Anonymous Inbound SIP Calls and Allow SIP Guests
- Go to connectivity –> firewall and allow only your office IP and VoIP Provider IP. Network interface should be Internet Default. Disable internet to all of the services.
- Create strong password for your extensions.
- Limit concurrent calls in your voip provider account as per your requirement. Disable international if not required. If you dial international then allow only countries you dial. Most of the voip providers allow you to set max call rate destination, you should use this feature too.