In addition to communicating with the local air traffic control
facility, aircraft are required to give the Iranian Air Defense Radar
(military) a ten minute "heads up" that 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
emergency frequency 121.5 Mhz while flying from Europe to Dubai.
It's too good not to pass along. The conversation went something like
Air Defense Radar: "Unknown aircraft at (location unknown), you are
in Iranian airspace. Identify yourself."
Aircraft: "This 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 fighter. Send 'em up!"
Air Defense Radar: (no response ... total silence)