It is possible to see what number the incoming caller has dialed by using a prefix.
For example, when you have a UK VoIP number and NL VoIP number you are able to instruct the PBX to put 'UK' in front of the callerID of the caller.
1. Login to the vPBX/PBX
2. Go to menu option ‘Incoming calls’
3. select the number from the 'All DID' list and double click on it
4. Enter the text you will use to identify the call (such as UK) in the ‘CID Prefix’ field
5. Apply and Save all changes
If in this example the UK DID is called by caller 3120123456 you will see their CLID as UK3120123456 so you know they called your UK number.