What are Ghost Calls?
A ghost call is the name given to phantom calls where your phone rings but nobody is on the other end of the call, nothing but silence. It is extremely annoying and depending on the source of the ghost call, it can happen frequently.
Sometimes the caller ID will be a strange number such as calls from 100, 1000, 1001 or the likes which is often a clear sign of a ghost call.
Who is Responsible for these Phantom Calls
Well first of all, it should be pointed out that this is rarely due to your phone provider.
Often these phantom phone calls are due to automated programs randomly dialing numbers or scanning IP (Internet Protocol) ports, often referred to as port scans, to try and find a way into your phone system.
They might be doing this to hack in and make calls on your dime, usually however these calls are from auto-dialers trying to make a connection, or to validate a number so it can be used by a telemarketer.
Stopping Ghost Calls
Provider Side Fixes
- We implement a number of firewalls and other security mechanisms to prevent this if the call is going through our servers.
- If you are getting unwanted calls that appear to be using valid numbers, note the time and number and we can check our system and if necessary block all calls from that caller.
End User Fixes
- If the Ghost call is going directly to your network or device, it needs to be blocked on your premises. Higher end firewalls can take care of the problem, however this functionality is usually not available with the typical home or small office router.
- The quickest solution is to modify a few settings on your phone or ATA adapter to block direct IP calls. Here are some examples:
Grandstream
Validate incoming sip message = Yes
Check SIP UserID for incoming INVITE = Yes
Allow Incoming SIP Messages from SIP Proxy Only = Yes
Yealink
Features -> General ->
Allow IP Call = Disabled
Accept SIP Trust Server Only = Enabled
or:
features.direct_ip_call_enable = 0
sip.trust_ctrl=1