What to do if you are receiving Ghost or Phantom calls from strange numbers
If you have received Ghost or Phantom calls from strange numbers and the calls are always silent then this is very likely that you have a local network vulnerability. The calls serve a warning that someone is trying to scan your internet connection and brute force your VoIP LAN on the well-known SIP UDP port 5060. The vulnerability is almost always a device in the DMZ or the port forwarding of SIP traffic from edge network devices such as routers. We STRONGLY recommend against both of the above practices!
Traffic MUST ALWAYS be restricted to VoIP networks you are connected to and VLANs for voice is best practice. Direct remote administration for your IP phones has some benefits but we recommend not to enable it. Please see the security section and read the articles or you can contact us for advice and best practice. If in doubt, consult a network/IT security specialist, the pros outweigh the cons exponentially.
We advise against self-configuration and provisioning as VoiceHost is able to remotely disable vulnerabilities such as 'Allow IP Calls' in Yealink phones for example.
In Summary, you should always do the following two things
Traffic MUST ALWAYS be restricted to trusted VoIP networks
Use our auto-provisioning service for Key Vendors and do not try to configure yourself unless you understand the risks.