In addition to communicating with the local Air Traffic Control facility, all aircraft in the Persian Gulf AOR are required to give the Iranian Air Defense Radar (military) a ten minute 'heads up' if they will be transiting Iranian airspace.
This is a common procedure for commercial aircraft and involves giving them your call sign, transponder code, type aircraft, and points of origin and destination.
I just flew with a guy who overheard this conversation on the VHF Guard (emergency) frequency 121.5 MHz while flying from Europe to Dubai .
The conversation went like this...
Iranian Air Defense Radar:
'Unknown aircraft you are in Iranian airspace. Identify yourself.'
Aircraft:
'This is a United States aircraft. I am in Iraqi airspace.'
Air Defense Radar:
'You are in Iranian airspace. If you do not depart our airspace we will launch interceptor aircraft!'
Aircraft:
'This is a United States Marine Corps FA-18 fighter. Send 'em up, I'll wait!'Air Defense Radar:
(no response ... total silence)God bless our troops.