Hi !
Two parties recieving call from each others but no one has dialed to other party….the recievers get connecting with strange numbers…
they are getting each others numbers comining with (+)sign
HOW CAN I CHECK THIS
VoIP, cellular, POTS? Calls coming across a PBX?
How are the numbers strange if they belong to the other party?
"they are getting each other's numbers with (+) sign"
What does the + sign mean in your country with regards to the phones.
BitHead may be right.. someone may be pranking them using Caller ID Spoofing. See if there are any common friends between the two - ofcourse if the two are friends, then that exponentially increases the number of "common" friends ( Even then, it won't definitively give you the culprit but maybe something to work on.