I have been out of the loop for awhile, however in the nineties we had a dial in system at work we used for guards to report when on site and when leaving a sit

I have been out of the loop for awhile, however in the nineties we had a dial in system at work we used for guards to report when on site and when leaving a site from work. We relied on ANI data from the phone company which contained the actual number the call was placed from. Surely the phone company has this data and could compare it in flight to what is being passed along as the caller id information which I was under the impression is wholly separate data. If anything do so smart phones could see both entries and flag suspicious calls